CVE-2026-10649

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.

This is classified as an Important flaw. An unauthenticated remote attacker can trigger a denial of service in Pacemaker's CIB remote listener by sending a crafted compressed message. This vulnerability exists before authentication, allowing an attacker with network access to a configured remote-port or remote-tls-port to cause the service to crash.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

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.