CVE-2026-81665

highpriority · track · 30EPSS 0.004 · 36 %ileDEFRUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.42% (36th) EPSS

CVSS 7.5 · high

Is it mine?

20 products

Check your exposure

Who says so?

2 sources

cert_bund · certfr

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · secalert@redhat.com USexploitability 1.6 · impact 5.9

v3.16.9mediumCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-122US

affected products (20)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
IBM AIX 7.2all versionscert_bundDEcpe:/o:ibm:aix:7.2
IBM AIX 7.3all versionscert_bundDEcpe:/o:ibm:aix:7.3
IBM MQ Operatorall versionscert_bundDEcpe:/a:ibm:mq:operator
IBM QRadar SIEMall versionscert_bundDEcpe:/a:ibm:qradar_siem:-
IBM VIOS 4.1all versionscert_bundDEcpe:/a:ibm:vios:4.1
IBM iall versionscert_bundDEcpe:/o:ibm:i:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat Enterprise Linux 10all versionscert_bundDEcpe:/o:redhat:enterprise_linux:10
Red Hat Enterprise Linux 10.0 Extended Update Supportall versionscert_bundDEcpe:/o:redhat:enterprise_linux:10.0_extended_update_support
Red Hat Enterprise Linux 9all versionscert_bundDEcpe:/o:redhat:enterprise_linux:9
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutionsall versionscert_bundDEcpe:/o:redhat:enterprise_linux:9.4_update_services_for_sap_solutions
Red Hat Enterprise Linux 9.6 Extended Update Supportall versionscert_bundDEcpe:/o:redhat:enterprise_linux:9.6_extended_update_support
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3419Red Hat Enterprise Linux (corosync, libevent, libsoup): Mehrere SchwachstellenDeutsch2026-09-16csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder Denial-of-Service-Zustände herbeizuführen.
CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR

sources

Which sources assert this record, and when.

cert_bund certfr NVD CVE.org MITRE

published 2026-09-04modified 2026-10-21

references (13) nvd

External citations — patches, advisories, analysis.

scry

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