CVE-2026-81665Corosync: corosync: heap-based buffer overflow in totempg assembly buffer during fragmented message reassembly
Updated under an hour ago ()
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It affects Red Hat Enterprise Linux 10 and 7 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-122
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 30, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux | from 0:3.1.10-1.el10_2.2 not affected | CNA record |
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support redhat:enterprise_linux_eus | from 0:3.1.9-1.el10_0.3 not affected | CNA record |
from 0:3.1.0-3.el8_4.3 not affected | CNA record | |
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support redhat:rhel_eus_long_life | from 0:3.1.0-3.el8_4.3 not affected | CNA record |
from 0:3.1.7-1.el8_8.2 not affected | CNA record | |
from 0:3.1.7-1.el8_8.2 not affected | CNA record | |
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support redhat:rhel_eus | from 0:3.1.9-2.el9_6.2 not affected | CNA record |
Red Hat Red Hat OpenShift Container Platform 4 redhat:openshift | 4 | CNA record |
References
- https://access.redhat.com/errata/RHSA-2026:67872vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:67873vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:67878vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:67879vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:67880vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:67881vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:68574vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:69277vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:69278vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:69279vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2026:69280vendor-advisory, x-refsource-redhat
- https://access.redhat.com/security/cve/CVE-2026-81665vdb-entry, x-refsource-redhat
- https://bugzilla.redhat.com/show_bug.cgi?id=2524910issue-tracking, x-refsource-redhat
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.