Pacemaker CIB Remote Listener DoS via Integer Overflow in Remote Message Decompression
CVE-2026-10649 is an integer overflow vulnerability in Pacemaker’s remote message decompression logic affecting the pre-authentication handling path for remote messages. The flaw is reported in pcmk__remote_message_xml() in lib/common/remote.c, reachable via the CIB remote listener path in daemons/based/based_remote.c. Attacker-controlled remote message header fields, including payload_offset, payload_compressed, and payload_uncompressed, are used in size calculations without sufficient bounds and consistency validation. Specifically, calculations such as 1 + header->payload_uncompressed and header->payload_offset + size_u can wrap, causing allocation of a destination buffer smaller than intended before BZ2_bzBuffToBuffDecompress() is invoked. A specially crafted compressed remote message sent before authentication can therefore trigger memory corruption in the listener process. The demonstrated outcome is a crash of the CIB remote listener, resulting in denial of service.
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Impact, mitigation & remediation
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Impact
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Mitigation
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remote-port or remote-tls-port so only trusted peers can reach it, for example with host-based or network firewalls. The provided content also notes that a Pacemaker service restart may be necessary for mitigation changes to fully apply.Remediation
Patch, then assume compromise.
remote-port or remote-tls-port.Exploits
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No public exploit code observed for this vulnerability.
Recent activity
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An integer overflow vulnerability in Pacemaker's remote message decompression process that can be exploited pre-authentication by a remote attacker to cause memory corruption and denial of service in the CIB remote listener.
An unauthenticated remote integer overflow vulnerability in Pacemaker's remote message decompression path that can cause memory corruption and denial of service in the CIB remote listener before authentication.
An important integer overflow vulnerability in Pacemaker's remote message decompression process that can be triggered pre-authentication over the network, causing memory corruption and denial of service in the CIB remote listener.
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