Vulnerability-Lookup

CERTFR-2026-AVI-0176

Vulnerability from certfr_avis - Published: 2026-02-17 - Updated: 2026-03-17

Une vulnérabilité a été découverte dans Mattermost Server. Elle permet à un attaquant de provoquer une atteinte à la confidentialité des données.

Solutions

Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation).

Impacted products

	Vendor	Product	Description
	Mattermost	Mattermost Server	Mattermost Server versions 11.3.x antérieures à 11.3.1

References

Title

Publication Time

Tags

Bulletin de sécurité Mattermost MMSA-2026-00579

2026-02-16

vendor-advisory

Show details on source website

JSON

To clipboard

{
  "$ref": "https://www.cert.ssi.gouv.fr/openapi.json",
  "affected_systems": [
    {
      "description": "Mattermost Server versions 11.3.x ant\u00e9rieures \u00e0 11.3.1",
      "product": {
        "name": "Mattermost Server",
        "vendor": {
          "name": "Mattermost",
          "scada": false
        }
      }
    }
  ],
  "affected_systems_content": "",
  "content": "## Solutions\n\nSe r\u00e9f\u00e9rer au bulletin de s\u00e9curit\u00e9 de l\u0027\u00e9diteur pour l\u0027obtention des correctifs (cf. section Documentation).",
  "cves": [
    {
      "name": "CVE-2026-2578",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-2578"
    }
  ],
  "initial_release_date": "2026-02-17T00:00:00",
  "last_revision_date": "2026-03-17T00:00:00",
  "links": [],
  "reference": "CERTFR-2026-AVI-0176",
  "revisions": [
    {
      "description": "Version initiale",
      "revision_date": "2026-02-17T00:00:00.000000"
    },
    {
      "description": "Ajout de l\u0027identifiant CVE-2026-2578 et modification du risque.",
      "revision_date": "2026-03-17T00:00:00.000000"
    }
  ],
  "risks": [
    {
      "description": "Atteinte \u00e0 la confidentialit\u00e9 des donn\u00e9es"
    }
  ],
  "summary": "Une vuln\u00e9rabilit\u00e9 a \u00e9t\u00e9 d\u00e9couverte dans Mattermost Server. Elle permet \u00e0 un attaquant de provoquer une atteinte \u00e0 la confidentialit\u00e9 des donn\u00e9es.",
  "title": "Vuln\u00e9rabilit\u00e9 dans Mattermost Server",
  "vendor_advisories": [
    {
      "published_at": "2026-02-16",
      "title": "Bulletin de s\u00e9curit\u00e9 Mattermost MMSA-2026-00579",
      "url": "https://mattermost.com/security-updates/"
    }
  ]
}

CVE-2026-2578 (GCVE-0-2026-2578)

Vulnerability from cvelistv5 – Published: 2026-03-16 11:58 – Updated: 2026-03-16 13:49

Title

Information Disclosure via WebSocket Event When Deleting Unrevealed Burn on Read Posts

Summary

Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579

Severity ?

4.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CWE

CWE-201 - Insertion of Sensitive Information Into Sent Data

Assigner

Mattermost

References

URL

Tags

https://mattermost.com/security-updates

vendor-advisory

Impacted products

	Vendor	Product	Version
	Mattermost	Mattermost	Affected: 11.3.0 , ≤ 11.3.0 (semver) Unaffected: 11.4.0 Unaffected: 11.3.1

Credits

Joshua Rogers

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-2578",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-16T13:42:18.043453Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-16T13:49:55.812Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Mattermost",
          "vendor": "Mattermost",
          "versions": [
            {
              "lessThanOrEqual": "11.3.0",
              "status": "affected",
              "version": "11.3.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "11.4.0"
            },
            {
              "status": "unaffected",
              "version": "11.3.1"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Joshua Rogers"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Mattermost versions 11.3.x \u003c= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 4.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-201",
              "description": "CWE-201: Insertion of Sensitive Information Into Sent Data",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-16T11:58:09.834Z",
        "orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
        "shortName": "Mattermost"
      },
      "references": [
        {
          "name": "MMSA-2026-00579",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://mattermost.com/security-updates"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Update Mattermost to versions 11.4.0, 11.3.1 or higher."
        }
      ],
      "source": {
        "advisory": "MMSA-2026-00579",
        "defect": [
          "https://mattermost.atlassian.net/browse/MM-67127"
        ],
        "discovery": "EXTERNAL"
      },
      "title": "Information Disclosure via WebSocket Event When Deleting Unrevealed Burn on Read Posts",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
    "assignerShortName": "Mattermost",
    "cveId": "CVE-2026-2578",
    "datePublished": "2026-03-16T11:58:09.834Z",
    "dateReserved": "2026-02-16T10:09:16.281Z",
    "dateUpdated": "2026-03-16T13:49:55.812Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CERTFR-2026-AVI-0176

Solutions

CVE-2026-2578 (GCVE-0-2026-2578)

Tags

Sightings

Nomenclature