CVE-2026-81665

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

HIGH 7.5

At a glance

Source: NVD
EPSS: EPSS 0.42 % · percentile 36 (2026-10-28)
State: PUBLISHED
Published: 2026-09-04 09:05 UTC
Updated: 2026-10-21 20:43 UTC
Assigner: redhat
NVD status: Awaiting Analysis

Description

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.

Weaknesses (CWE)

CWE-122 — Heap-based Buffer Overflow

References

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	redhat
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	NVD · secalert@redhat.com (Secondary)

European references

ENISA EUVD · EUVD-2026-70978
GCVE · GCVE-0-2026-81665

CERT-FR advisories

CERTFR-2026-AVI-1336 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected products

Product	Versions
Red Hat · Red Hat Enterprise Linux 10	unaffected 0:3.1.10-1.el10_2.2 < *
Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support	unaffected 0:3.1.9-1.el10_0.3 < *
Red Hat · Red Hat Enterprise Linux 7 Extended Lifecycle Support	unaffected 0:2.4.5-7.el7_9.4 < *
Red Hat · Red Hat Enterprise Linux 8	unaffected 0:3.1.8-1.el8_10.2 < *
Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support	unaffected 0:3.1.0-3.el8_4.3 < *
Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On	unaffected 0:3.1.0-3.el8_4.3 < *
Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support	unaffected 0:3.1.5-2.el8_6.2 < *
Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On	unaffected 0:3.1.5-2.el8_6.2 < *
Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service	unaffected 0:3.1.7-1.el8_8.2 < *
Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions	unaffected 0:3.1.7-1.el8_8.2 < *
Red Hat · Red Hat Enterprise Linux 9	unaffected 0:3.1.10-1.el9_8.2 < *
Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions	unaffected 0:3.1.7-1.el9_2.2 < *
Red Hat · Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions	unaffected 0:3.1.8-1.el9_4.2 < *
Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support	unaffected 0:3.1.9-2.el9_6.2 < *
Red Hat · Red Hat OpenShift Container Platform 4
Red Hat · Red Hat OpenShift Container Platform 4

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD