CVE record · CVE-2026-81665

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

CVSS 7.5 HighEPSS 0.0042 · 36th percentile

Published by the CVE Program (CNA: redhat) at 4 Sept 2026, 09:05 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Red Hat	Red Hat Enterprise Linux 10 Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.10-1.el10_2.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 10.0 Extended Update Support Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.9-1.el10_0.3 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 7 Extended Lifecycle Support Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:2.4.5-7.el7_9.4 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8 Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.8-1.el8_10.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.0-3.el8_4.3 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.0-3.el8_4.3 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.5-2.el8_6.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.5-2.el8_6.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8.8 Telecommunications Update Service Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.7-1.el8_8.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.7-1.el8_8.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9 Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.10-1.el9_8.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.7-1.el9_2.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.8-1.el9_4.2 to before * rpm Other versions: affected
Red Hat	Red Hat Enterprise Linux 9.6 Extended Update Support Package name: corosync https://access.redhat.com/downloads/content/package-browser/	unaffected 0:3.1.9-2.el9_6.2 to before * rpm Other versions: affected
Red Hat	Red Hat OpenShift Container Platform 4 Package name: openshift/ose-rhel-coreos-9 https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: affected
Red Hat	Red Hat OpenShift Container Platform 4 Package name: rhcos https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected
Red Hat	Red Hat OpenShift Container Platform 5 Package name: openshift/ose-rhel-coreos-9 https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: affected
Red Hat	Red Hat OpenShift Container Platform 5 Package name: rhcos https://access.redhat.com/downloads/content/package-browser/	No versions given Other versions: unaffected

Identifiers: CVE-2026-81665
CNA: redhat
Weakness (CWE): CWE-122
Tags: Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 10.0 Extended Update Support
Red Hat Enterprise Linux 7 Extended Lifecycle Support
Red Hat Enterprise Linux 8
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
Memory corruption
Published: 4 Sept 2026
Updated: 2 Nov 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
7.5	High	3.1	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	CNA (redhat)

CISA KEV Not listed.
EPSS 0.0042, the 36th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

4 Sept 2026, 09:05 UTC Confirmed by the CVE List
4 Sept 2026, 09:17 UTC Confirmed by NVD

Sources

References from the CNA

access.redhat.com/errata/RHSA-2026:67872 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:67873 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:67878 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:67879 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:67880 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:67881 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:68574 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:69277 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:69278 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:69279 vendor-advisoryredhat
access.redhat.com/errata/RHSA-2026:69280 vendor-advisoryredhat
access.redhat.com/security/cve/CVE-2026-81665 vdb-entryredhat
bugzilla.redhat.com/show_bug.cgi?id=2524910 issue-trackingredhat

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.