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974 vulnerabilities found for mattermost_server by mattermost
CVE-2026-96260 (GCVE-0-2026-96260)
Vulnerability from nvd – Published: 2026-09-22 20:34 – Updated: 2026-09-23 15:06
VLAI
EPSS
VEX
Title
Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user
Summary
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-23 15:05 UTC
CWE
- CWE-789 - Memory Allocation with Excessive Size Value
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.1
(semver)
Affected: 11.8.0 , ≤ 11.8.5 (semver) Affected: 11.7.0 , ≤ 11.7.10 (semver) Affected: 11.10.0 , ≤ 11.10.1 (semver) Unaffected: 11.11.0 Unaffected: 11.9.2 Unaffected: 11.8.6 Unaffected: 11.7.11 Unaffected: 11.10.2 |
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CVE-2026-96259 (GCVE-0-2026-96259)
Vulnerability from nvd – Published: 2026-09-22 20:34 – Updated: 2026-09-23 13:10
VLAI
EPSS
VEX
Title
Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator
Summary
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776
Severity
5.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-23 13:10 UTC
CWE
- CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.1
(semver)
Affected: 11.8.0 , ≤ 11.8.5 (semver) Affected: 11.7.0 , ≤ 11.7.10 (semver) Affected: 11.10.0 , ≤ 11.10.1 (semver) Unaffected: 11.11.0 Unaffected: 11.9.2 Unaffected: 11.8.6 Unaffected: 11.7.11 Unaffected: 11.10.2 |
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CVE-2026-95666 (GCVE-0-2026-95666)
Vulnerability from nvd – Published: 2026-09-22 13:11 – Updated: 2026-09-22 13:57
VLAI
EPSS
VEX
Title
Unbounded post ID array in the bulk reactions endpoint allows denial of service
Summary
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to limit the length of the post ID array accepted by the bulk reactions endpoint which allows an authenticated user to cause excessive database load via a crafted request to {{POST /api/v4/posts/ids/reactions}}.. Mattermost Advisory ID: MMSA-2026-00771
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-22 13:55 UTC
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.1
(semver)
Affected: 11.8.0 , ≤ 11.8.5 (semver) Affected: 11.7.0 , ≤ 11.7.10 (semver) Affected: 11.10.0 , ≤ 11.10.1 (semver) Unaffected: 11.11.0 Unaffected: 11.9.2 Unaffected: 11.8.6 Unaffected: 11.7.11 Unaffected: 11.10.2 |
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CVE-2026-91181 (GCVE-0-2026-91181)
Vulnerability from nvd – Published: 2026-09-14 21:21 – Updated: 2026-09-16 03:56
VLAI
EPSS
VEX
Title
Data Retention Teams Endpoint Leaks Private Team Invite ID
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret invite_id and email, and use it to join the team without authorization, via GET /api/v4/data_retention/policies/{policy_id}/teams.. Mattermost Advisory ID: MMSA-2026-00702
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-15 00:00 UTC
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-12985 (GCVE-0-2026-12985)
Vulnerability from nvd – Published: 2026-09-14 14:09 – Updated: 2026-09-15 03:56
VLAI
EPSS
VEX
Title
Mattermost DCR redirect URI allowlist bypass via improper URL component validation
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 Mattermost failed to validate Dynamic Client Registration redirect URIs by URL component (matching glob patterns against the raw URI string instead) which allows a remote unauthenticated attacker to register an OAuth client with an attacker-controlled callback host that bypasses the configured redirect URI allowlist via a crafted redirect URI that places an allowlisted host/path suffix inside the query string.. Mattermost Advisory ID: MMSA-2026-00700
Severity
6.8 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 00:00 UTC
CWE
- CWE-601 - URL Redirection to Untrusted Site (“Open Redirect”)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 |
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CVE-2026-86349 (GCVE-0-2026-86349)
Vulnerability from nvd – Published: 2026-09-14 13:51 – Updated: 2026-09-14 19:23
VLAI
EPSS
VEX
Title
Mattermost Server Algorithmic DoS via Unbounded Markdown Block Nesting
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.8, 10.11.x <= 10.11.22 fail to limit the nesting depth in the server-side Markdown parser which allows an authenticated attacker to cause a denial of service (CPU resource exhaustion) via a crafted post containing deeply nested blockquotes or list items.. Mattermost Advisory ID: MMSA-2026-00707
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:13 UTC
CWE
- CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.8 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.9 Unaffected: 10.11.23 |
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CVE-2026-82920 (GCVE-0-2026-82920)
Vulnerability from nvd – Published: 2026-09-14 13:59 – Updated: 2026-09-14 19:23
VLAI
EPSS
VEX
Title
Mattermost ABAC parent policy bypass via policy update endpoint
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/access_control_policies request with an empty imports list.. Mattermost Advisory ID: MMSA-2026-00724
Severity
5.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:13 UTC
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 |
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CVE-2026-9812 (GCVE-0-2026-9812)
Vulnerability from nvd – Published: 2026-09-14 10:43 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Missing property field ownership validation in Playbooks run property update endpoint
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate that a property field belongs to the specified run before updating its value which allows an authenticated user with run property-management access to crash the Playbooks plugin via a REST request referencing a property field that belongs to a different run. Mattermost Advisory ID: MMSA-2026-00684
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
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CVE-2026-8821 (GCVE-0-2026-8821)
Vulnerability from nvd – Published: 2026-09-14 10:42 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Playbooks run owner channel membership permission bypass
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel member-management permission during playbook run creation, allowing an authenticated channel member to add an arbitrary user to a restricted channel via the run owner field.. Mattermost Advisory ID: MMSA-2026-00677
Severity
7.1 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-862 - Missing Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
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Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-5132 (GCVE-0-2026-5132)
Vulnerability from nvd – Published: 2026-09-14 10:41 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Unbounded zlib decompression in Calls SDP WebSocket messages
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit size of unpacked SDP messages compressed with zlib, which allows attacker to deny service or crash server via sending many SDP messages that unpack to large size.. Mattermost Advisory ID: MMSA-2026-00643
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
1 reference
| URL | Tags |
|---|---|
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Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-15814 (GCVE-0-2026-15814)
Vulnerability from nvd – Published: 2026-09-14 10:39 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Uploading a crafted image causes excessive memory allocation in the Mattermost Server
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:02 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
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Affected:
11.9.0 , ≤ 11.9.0
(semver)
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CVE-2026-14344 (GCVE-0-2026-14344)
Vulnerability from nvd – Published: 2026-09-14 10:33 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Inconsistent authorization checks in Mattermost Boards endpoints
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce the board-creation permission which allows an unauthorized authenticated user to create boards via the board duplicate, boards-and-blocks, and archive-import endpoints.. Mattermost Advisory ID: MMSA-2026-00715
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:02 UTC
CWE
- CWE-862 - Missing Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-14259 (GCVE-0-2026-14259)
Vulnerability from nvd – Published: 2026-09-14 10:26 – Updated: 2026-09-14 19:36
VLAI
EPSS
VEX
Title
Board archive import bypasses team board creation permissions
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to enforce board creation permissions when importing archive files which allows an authenticated non-guest team member to create Open or Private boards despite administrator restrictions via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00712
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:35 UTC
CWE
- CWE-862 - Missing Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-13417 (GCVE-0-2026-13417)
Vulnerability from nvd – Published: 2026-09-14 10:44 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Boards plugin denial of service via unvalidated block fields.properties
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creation which allows an authenticated user with editor access to a board to crash the Boards plugin worker and trigger a denial of service via a child block whose `fields.properties` is a non-object value. Mattermost Advisory ID: MMSA-2026-00710
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-12882 (GCVE-0-2026-12882)
Vulnerability from nvd – Published: 2026-09-14 10:30 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Mattermost Markdown autolink parsing denial of service
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to parse Markdown autolinks with unmatched trailing closing parentheses in linear time, which allows an authenticated user with permission to create posts to cause excessive server CPU consumption and degrade availability for other users via specially crafted post or message attachment content. Mattermost Advisory ID: MMSA-2026-00703
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:02 UTC
CWE
- CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-11993 (GCVE-0-2026-11993)
Vulnerability from nvd – Published: 2026-09-14 10:29 – Updated: 2026-09-14 19:36
VLAI
EPSS
VEX
Title
Fix authenticated members disabling file content indexing server-wide via extraction pool exhaustion
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly enforce the limit of concurrent files being processed and handled failed files, which allows a user with permission to upload files to spawn more goroutines than intended and block the indexing of other files via uploading heavy files constantly to the server.. Mattermost Advisory ID: MMSA-2026-00696
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:36 UTC
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-10556 (GCVE-0-2026-10556)
Vulnerability from nvd – Published: 2026-09-14 10:46 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Unauthenticated webhook request with null notification entry could crash the Microsoft Calendar plugin.
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate null entries in Microsoft Graph webhook notification payloads, which allows an unauthenticated attacker to crash the Microsoft Calendar plugin process and deny calendar integration service to all users on the instance via a crafted {{POST}} request to the public webhook endpoint.. Mattermost Advisory ID: MMSA-2026-00693
Severity
5.3 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:04 UTC
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-10542 (GCVE-0-2026-10542)
Vulnerability from nvd – Published: 2026-09-14 10:37 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Playbooks channel action update validation issue
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692
Severity
5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:02 UTC
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-96260 (GCVE-0-2026-96260)
Vulnerability from cvelistv5 – Published: 2026-09-22 20:34 – Updated: 2026-09-23 15:06
VLAI
EPSS
VEX
Title
Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user
Summary
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-23 15:05 UTC
CWE
- CWE-789 - Memory Allocation with Excessive Size Value
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.1
(semver)
Affected: 11.8.0 , ≤ 11.8.5 (semver) Affected: 11.7.0 , ≤ 11.7.10 (semver) Affected: 11.10.0 , ≤ 11.10.1 (semver) Unaffected: 11.11.0 Unaffected: 11.9.2 Unaffected: 11.8.6 Unaffected: 11.7.11 Unaffected: 11.10.2 |
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CVE-2026-96259 (GCVE-0-2026-96259)
Vulnerability from cvelistv5 – Published: 2026-09-22 20:34 – Updated: 2026-09-23 13:10
VLAI
EPSS
VEX
Title
Mattermost server-side request forgery via OAuth endpoints configurable by a System Administrator
Summary
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776
Severity
5.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-23 13:10 UTC
CWE
- CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.1
(semver)
Affected: 11.8.0 , ≤ 11.8.5 (semver) Affected: 11.7.0 , ≤ 11.7.10 (semver) Affected: 11.10.0 , ≤ 11.10.1 (semver) Unaffected: 11.11.0 Unaffected: 11.9.2 Unaffected: 11.8.6 Unaffected: 11.7.11 Unaffected: 11.10.2 |
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CVE-2026-95666 (GCVE-0-2026-95666)
Vulnerability from cvelistv5 – Published: 2026-09-22 13:11 – Updated: 2026-09-22 13:57
VLAI
EPSS
VEX
Title
Unbounded post ID array in the bulk reactions endpoint allows denial of service
Summary
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to limit the length of the post ID array accepted by the bulk reactions endpoint which allows an authenticated user to cause excessive database load via a crafted request to {{POST /api/v4/posts/ids/reactions}}.. Mattermost Advisory ID: MMSA-2026-00771
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-22 13:55 UTC
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.1
(semver)
Affected: 11.8.0 , ≤ 11.8.5 (semver) Affected: 11.7.0 , ≤ 11.7.10 (semver) Affected: 11.10.0 , ≤ 11.10.1 (semver) Unaffected: 11.11.0 Unaffected: 11.9.2 Unaffected: 11.8.6 Unaffected: 11.7.11 Unaffected: 11.10.2 |
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CVE-2026-91181 (GCVE-0-2026-91181)
Vulnerability from cvelistv5 – Published: 2026-09-14 21:21 – Updated: 2026-09-16 03:56
VLAI
EPSS
VEX
Title
Data Retention Teams Endpoint Leaks Private Team Invite ID
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret invite_id and email, and use it to join the team without authorization, via GET /api/v4/data_retention/policies/{policy_id}/teams.. Mattermost Advisory ID: MMSA-2026-00702
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-15 00:00 UTC
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-12985 (GCVE-0-2026-12985)
Vulnerability from cvelistv5 – Published: 2026-09-14 14:09 – Updated: 2026-09-15 03:56
VLAI
EPSS
VEX
Title
Mattermost DCR redirect URI allowlist bypass via improper URL component validation
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 Mattermost failed to validate Dynamic Client Registration redirect URIs by URL component (matching glob patterns against the raw URI string instead) which allows a remote unauthenticated attacker to register an OAuth client with an attacker-controlled callback host that bypasses the configured redirect URI allowlist via a crafted redirect URI that places an allowlisted host/path suffix inside the query string.. Mattermost Advisory ID: MMSA-2026-00700
Severity
6.8 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 00:00 UTC
CWE
- CWE-601 - URL Redirection to Untrusted Site (“Open Redirect”)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 |
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CVE-2026-82920 (GCVE-0-2026-82920)
Vulnerability from cvelistv5 – Published: 2026-09-14 13:59 – Updated: 2026-09-14 19:23
VLAI
EPSS
VEX
Title
Mattermost ABAC parent policy bypass via policy update endpoint
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 fail to enforce authorization boundaries on the access control policy update endpoint which allows a channel or team administrator to detach a system-assigned ABAC parent policy via a crafted PUT /api/v4/access_control_policies request with an empty imports list.. Mattermost Advisory ID: MMSA-2026-00724
Severity
5.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:13 UTC
CWE
- CWE-863 - Incorrect Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 |
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CVE-2026-86349 (GCVE-0-2026-86349)
Vulnerability from cvelistv5 – Published: 2026-09-14 13:51 – Updated: 2026-09-14 19:23
VLAI
EPSS
VEX
Title
Mattermost Server Algorithmic DoS via Unbounded Markdown Block Nesting
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.8, 10.11.x <= 10.11.22 fail to limit the nesting depth in the server-side Markdown parser which allows an authenticated attacker to cause a denial of service (CPU resource exhaustion) via a crafted post containing deeply nested blockquotes or list items.. Mattermost Advisory ID: MMSA-2026-00707
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:13 UTC
CWE
- CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.8 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.9 Unaffected: 10.11.23 |
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CVE-2026-10556 (GCVE-0-2026-10556)
Vulnerability from cvelistv5 – Published: 2026-09-14 10:46 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Unauthenticated webhook request with null notification entry could crash the Microsoft Calendar plugin.
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate null entries in Microsoft Graph webhook notification payloads, which allows an unauthenticated attacker to crash the Microsoft Calendar plugin process and deny calendar integration service to all users on the instance via a crafted {{POST}} request to the public webhook endpoint.. Mattermost Advisory ID: MMSA-2026-00693
Severity
5.3 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:04 UTC
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-13417 (GCVE-0-2026-13417)
Vulnerability from cvelistv5 – Published: 2026-09-14 10:44 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Boards plugin denial of service via unvalidated block fields.properties
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creation which allows an authenticated user with editor access to a board to crash the Boards plugin worker and trigger a denial of service via a child block whose `fields.properties` is a non-object value. Mattermost Advisory ID: MMSA-2026-00710
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-9812 (GCVE-0-2026-9812)
Vulnerability from cvelistv5 – Published: 2026-09-14 10:43 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Missing property field ownership validation in Playbooks run property update endpoint
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate that a property field belongs to the specified run before updating its value which allows an authenticated user with run property-management access to crash the Playbooks plugin via a REST request referencing a property field that belongs to a different run. Mattermost Advisory ID: MMSA-2026-00684
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-8821 (GCVE-0-2026-8821)
Vulnerability from cvelistv5 – Published: 2026-09-14 10:42 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Playbooks run owner channel membership permission bypass
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel member-management permission during playbook run creation, allowing an authenticated channel member to add an arbitrary user to a restricted channel via the run owner field.. Mattermost Advisory ID: MMSA-2026-00677
Severity
7.1 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-862 - Missing Authorization
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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CVE-2026-5132 (GCVE-0-2026-5132)
Vulnerability from cvelistv5 – Published: 2026-09-14 10:41 – Updated: 2026-09-14 11:19
VLAI
EPSS
VEX
Title
Unbounded zlib decompression in Calls SDP WebSocket messages
Summary
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit size of unpacked SDP messages compressed with zlib, which allows attacker to deny service or crash server via sending many SDP messages that unpack to large size.. Mattermost Advisory ID: MMSA-2026-00643
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 11:03 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.9.0 , ≤ 11.9.0
(semver)
Affected: 11.8.0 , ≤ 11.8.4 (semver) Affected: 11.7.0 , ≤ 11.7.7 (semver) Affected: 10.11.0 , ≤ 10.11.22 (semver) Unaffected: 11.10.0 Unaffected: 11.9.1 Unaffected: 11.8.5 Unaffected: 11.7.8 Unaffected: 10.11.23 |
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{
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{
"lessThanOrEqual": "11.7.7",
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"version": "11.7.0",
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{
"lessThanOrEqual": "10.11.22",
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{
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}
],
"credits": [
{
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"type": "finder",
"value": "daw10"
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],
"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.9.x \u003c= 11.9.0, 11.8.x \u003c= 11.8.4, 11.7.x \u003c= 11.7.7, 10.11.x \u003c= 10.11.22 fail to limit size of unpacked SDP messages compressed with zlib, which allows attacker to deny service or crash server via sending many SDP messages that unpack to large size.. Mattermost Advisory ID: MMSA-2026-00643"
}
],
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{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-409",
"description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-14T10:41:42.387Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00643",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8, 10.11.23 or higher."
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],
"source": {
"advisory": "MMSA-2026-00643",
"defect": [
"https://mattermost.atlassian.net/browse/MM-68130"
],
"discovery": "EXTERNAL"
},
"title": "Unbounded zlib decompression in Calls SDP WebSocket messages",
"x_generator": {
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}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-5132",
"datePublished": "2026-09-14T10:41:42.387Z",
"dateReserved": "2026-03-30T09:58:00.256Z",
"dateUpdated": "2026-09-14T11:19:45.000Z",
"state": "PUBLISHED"
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