A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a memory corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.

ubuntu_linux USN-8687-1: Ubuntu 18.04 LTS / Ubuntu 20.04 LTS / Ubuntu 22.04 LTS / Ubuntu 24.04 LTS / Ubuntu Pro Realtime 22.04 LTS / Ubuntu Pro Realtime 24.04 LTS : p11-kit vulnerabilities (USN-8687-1)

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel,
    could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can
    cause the system to miscalculate memory allocation for nested attributes. This leads to a memory
    corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing
    process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.
    (CVE-2026-18938)

The remote Fedora 43 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-e281fdcb69 advisory.

    rpc: guard against overflow when decoding nested attributes (CVE-2026-18938)     Only affects 32 bit systems

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-110c1a7742 advisory.

    rpc: guard against overflow when decoding nested attributes (CVE-2026-18938)     Only affects 32 bit systems

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel,     could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can     cause the system to miscalculate memory allocation for nested attributes. This leads to a memory     corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing     process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.
    (CVE-2026-18938)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of p11-kit installed on the remote host is prior to 0.26.5. It is, therefore, affected by a vulnerability as referenced in the SSA:2026-218-02 advisory.

    New p11-kit packages are available for Slackware 15.0 and -current to fix a security issue.

Tenable has extracted the preceding description block directly from the p11-kit security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Type	Severity
455434	Echo: p11-kit: security update to 0.25.5-3+e2	Tenable Cloud Security	Echo Local Security Checks	Local	medium
455434	Echo: p11-kit: security update to 0.25.5-3+e2	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
334461	Fedora 43 : p11-kit (2026-e281fdcb69)	Nessus	Fedora Local Security Checks	Local	medium
333506	Fedora 44 : p11-kit (2026-110c1a7742)	Nessus	Fedora Local Security Checks	Local	medium
333324	Linux Distros Unpatched Vulnerability : CVE-2026-18938	Nessus	Misc.	Local	medium
333265	Slackware Linux 15.0 / current p11-kit Vulnerability (SSA:2026-218-02)	Nessus	Slackware Local Security Checks	Local	medium

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