CVE-2026-10649

Pacemaker: pacemaker: denial of service via integer overflow in remote message decompression

publishedCWE-190

A flaw was found in Pacemaker. An unauthenticated remote attacker can exploit an integer overflow vulnerability in the remote message decompression process. By sending a specially crafted compressed remote message before authentication, an attacker can cause memory corruption, leading to a denial of service (DoS) in the CIB remote listener. This can result in the affected service crashing.

Technical severity8.6 highCVSS 3.1 · CNA: redhat

Published2026-06-16Source updated 2026-11-04

Collected2026-11-042 attributed sources

Fixes and workarounds

Workaround

Disable the Pacemaker CIB remote listener if it is not actively used. If the listener is required, restrict network access to trusted hosts by configuring firewall rules to limit inbound connections to the `remote-port` or `remote-tls-port`. These actions reduce the attack surface by limiting unauthenticated network exposure to the vulnerable component. A restart of the Pacemaker service may be necessary for these changes to be fully applied.

Source: CNA: redhat

Fix

RHSA-2026:43606: Red Hat Enterprise Linux Server HighAvailability (v. 7 ELS), Red Hat Enterprise Linux Server ResilientStorage (v. 7 ELS) RHSA-2026:41041: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux High Availability EUS (v. 10.0) RHSA-2026:40833: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux High Availability (v. 10) RHSA-2026:39322: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux HighAvailability (v. 8), Red Hat Enterprise Linux ResilientStorage (v. 8) RHSA-2026:42075: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4), Red Hat Enterprise Linux High Availability AUS (v.8.4), Red Hat Enterprise Linux HighAvailability EUS EXTENSION (v.8.4) RHSA-2026:42076: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6), Red Hat Enterprise Linux High Availability EUS EXTENSION (v.8.6) RHSA-2026:42041: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8), Red Hat Enterprise Linux High Availability E4S (v.8.8), Red Hat Enterprise Linux High Availability TUS (v.8.8) RHSA-2026:41042: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux High Availability EUS (v.9.6), Red Hat Enterprise Linux Resilient Storage EUS (v.9.6) RHSA-2026:39323: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux High Availability (v. 9), Red Hat Enterprise Linux Resilient Storage (v. 9) RHSA-2026:41044: Red Hat Enterprise Linux High Availability E4S (v.9.2), Red Hat Enterprise Linux Resilient Storage E4S (v.9.2) RHSA-2026:41043: Red Hat Enterprise Linux High Availability E4S (v.9.4), Red Hat Enterprise Linux Resilient Storage E4S (v.9.4)

Source: ADP: redhat-SADP

Workaround

Source: ADP: redhat-SADP

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
Red Hat Enterprise Linux 10 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:3.0.1-5.el10_2.1; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 10.0 Extended Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:3.0.0-5.3.el10_0; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 7 Extended Lifecycle Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:1.1.23-1.el7_9.2; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.7-5.6.el8_10; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.0.5-9.el8_4.12; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.0.5-9.el8_4.12; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.2-4.el8_6.11; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.2-4.el8_6.11; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.8 Telecommunications Update Service Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.5-9.7.el8_8; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.5-9.7.el8_8; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.10-3.el9_8; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.5-9.el9_2.7; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.7-5.5.el9_4; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9.6 Extended Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.9-1.4.el9_6; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 6 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	CNA: redhat
Red Hat OpenShift Container Platform 4 Red Hat `openshift/ose-rhel-coreos-9` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	CNA: redhat
Red Hat OpenShift Container Platform 5 Red Hat `openshift/ose-rhel-coreos-9` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	CNA: redhat
Red Hat Enterprise Linux 10 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:3.0.1-5.el10_2.1; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 10.0 Extended Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:3.0.0-5.3.el10_0; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 7 Extended Lifecycle Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:1.1.23-1.el7_9.2; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.7-5.6.el8_10; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.0.5-9.el8_4.12; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.0.5-9.el8_4.12; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.2-4.el8_6.11; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.2-4.el8_6.11; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8.8 Telecommunications Update Service Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.5-9.7.el8_8; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.5-9.7.el8_8; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 9 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.10-3.el9_8; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.5-9.el9_2.7; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.7-5.5.el9_4; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 9.6 Extended Update Support Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	≥ 0:2.1.9-1.4.el9_6; < * (unaffected, rpm) Other versions: affected	ADP: redhat-SADP
Red Hat Enterprise Linux 6 Red Hat `pacemaker` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	ADP: redhat-SADP
Red Hat OpenShift Container Platform 4 Red Hat `rhcos` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unaffected	ADP: redhat-SADP

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 8.6 high	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H`	CNA: redhat
3.1 / 8.6 high	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H`	ADP: redhat-SADP

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://access.redhat.com/errata/RHSA-2026:39322CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39323CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:40833CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41041CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41042CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41043CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41044CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:42041CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:42075CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:42076CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:43606CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-10649CNA: redhat · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462817CNA: redhat · issue-tracking, x_refsource_REDHAT
https://github.com/clusterLabs/pacemaker/pull/4128CNA: redhat
http://www.openwall.com/lists/oss-security/2026/06/16/6ADP: CVE
https://access.redhat.com/security/cve/CVE-2026-10649ADP: redhat-SADP · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2462817ADP: redhat-SADP · issue-tracking, x_refsource_REDHAT
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-10649.jsonADP: redhat-SADP · x_sadp-csaf-vex
https://access.redhat.com/errata/RHSA-2026:43606ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41041ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:40833ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39322ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:42075ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:42076ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:42041ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41042ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:39323ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41044ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:41043ADP: redhat-SADP · vendor-advisory, x_refsource_REDHAT

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