CVE-2026-4878

Description

A flaw was found in libcap. A local unprivileged user can exploit a Time-of-check-to-time-of-use (TOCTOU) race condition in the `cap_set_file()` function. This allows an attacker with write access to a parent directory to redirect file capability updates to an attacker-controlled file. By doing so, capabilities can be injected into or stripped from unintended executables, leading to privilege escalation.

CVSS Vector

References

• https://access.redhat.com/security/cve/CVE-2026-4878
• https://bugzilla.redhat.com/show_bug.cgi?id=2447554
• https://bugzilla.redhat.com/show_bug.cgi?id=2451615
• http://www.openwall.com/lists/oss-security/2026/04/07/14
• http://www.openwall.com/lists/oss-security/2026/04/07/4
• http://www.openwall.com/lists/oss-security/2026/04/08/9
• http://www.openwall.com/lists/oss-security/2026/04/09/5
• http://www.openwall.com/lists/oss-security/2026/04/09/6