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.
References10
- access.redhat.com/errata/RHSA-2026:67872
- access.redhat.com/errata/RHSA-2026:67873
- access.redhat.com/errata/RHSA-2026:67878
- access.redhat.com/errata/RHSA-2026:67879
- access.redhat.com/errata/RHSA-2026:67880
- access.redhat.com/errata/RHSA-2026:67881
- access.redhat.com/errata/RHSA-2026:68574
- access.redhat.com/errata/RHSA-2026:69277
- access.redhat.com/errata/RHSA-2026:69278
- access.redhat.com/errata/RHSA-2026:69279
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 36 · as of 3 November 2026
- CWE
- CWE-122
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