Vulnerability-Lookup

GHSA-VJ89-2C25-485X

Vulnerability from github – Published: 2026-09-04 09:32 – Updated: 2026-09-17 12:31

Details

A heap-based buffer overflow was found in Corosync's Totem Process Group (totempg) message reassembly. When processing fragmented multicast messages, the buffer used to reassemble fragments lacks a runtime bounds check in release builds. A network-adjacent attacker able to send crafted multicast protocol messages to the cluster could cause a heap buffer overflow with attacker-controlled data. This can crash the Corosync daemon, causing a denial of service to the entire cluster, and may potentially allow further exploitation given sufficient heap-corruption control.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-81665"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-04T09:17:11Z",
    "severity": "HIGH"
  },
  "details": "A heap-based buffer overflow was found in Corosync\u0027s Totem Process Group (totempg) message reassembly. When processing fragmented multicast messages, the buffer used to reassemble fragments lacks a runtime bounds check in release builds. A network-adjacent attacker able to send crafted multicast protocol messages to the cluster could cause a heap buffer overflow with attacker-controlled data. This can crash the Corosync daemon, causing a denial of service to the entire cluster, and may potentially allow further exploitation given sufficient heap-corruption control.",
  "id": "GHSA-vj89-2c25-485x",
  "modified": "2026-09-17T12:31:57Z",
  "published": "2026-09-04T09:32:00Z",
  "references": [
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      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81665"
    },
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CVE-2026-81665 (GCVE-0-2026-81665)

Vulnerability from cvelistv5 – Published: 2026-09-04 09:05 – Updated: 2026-09-17 11:43

Title

Corosync: corosync: heap-based buffer overflow in totempg assembly buffer during fragmented message reassembly

Summary

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-04 17:09 UTC

CWE

CWE-122 - Heap-based Buffer Overflow

Assigner

redhat redhat root

References

8 references

URL	Tags
https://access.redhat.com/errata/RHSA-2026:67872	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:67873	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:67878	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:67879	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:67881	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:68574	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-81665	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2524910	issue-trackingx_refsource_REDHAT

Impacted products

8 products

Vendor	Product	Version
Red Hat	Red Hat Enterprise Linux 10	Unaffected: 0:3.1.10-1.el10_2.2 , < * (rpm) cpe:/o:redhat:enterprise_linux:10.2
Red Hat	Red Hat Enterprise Linux 10.0 Extended Update Support	Unaffected: 0:3.1.9-1.el10_0.3 , < * (rpm) cpe:/o:redhat:enterprise_linux_eus:10.0
Red Hat	Red Hat Enterprise Linux 7 Extended Lifecycle Support	Unaffected: 0:2.4.5-7.el7_9.4 , < * (rpm) cpe:/o:redhat:enterprise_linux:7::server
Red Hat	Red Hat Enterprise Linux 9	Unaffected: 0:3.1.10-1.el9_8.2 , < * (rpm) cpe:/a:redhat:enterprise_linux:9::appstream cpe:/a:redhat:enterprise_linux:9::crb cpe:/a:redhat:enterprise_linux:9::highavailability cpe:/a:redhat:enterprise_linux:9::resilientstorage
Red Hat	Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions	Unaffected: 0:3.1.8-1.el9_4.2 , < * (rpm) cpe:/a:redhat:rhel_e4s:9.4::appstream cpe:/a:redhat:rhel_e4s:9.4::highavailability cpe:/a:redhat:rhel_e4s:9.4::resilientstorage
Red Hat	Red Hat Enterprise Linux 9.6 Extended Update Support	Unaffected: 0:3.1.9-2.el9_6.2 , < * (rpm) cpe:/a:redhat:rhel_eus:9.6::appstream cpe:/a:redhat:rhel_eus:9.6::crb cpe:/a:redhat:rhel_eus:9.6::highavailability cpe:/a:redhat:rhel_eus:9.6::resilientstorage
Red Hat	Red Hat Enterprise Linux 8	cpe:/o:redhat:enterprise_linux:8
Red Hat	Red Hat OpenShift Container Platform 4	cpe:/a:redhat:openshift:4

Date Public

2026-09-04 08:30

Credits

Red Hat would like to thank Tristan Madani (Talence Security) for reporting this issue.

Show details on NVD website

JSON

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Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.