Time-of-check Time-of-use (TOCTOU) Affecting libcap2 package, versions <1:2.66-5ubuntu2.4


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.21% (11th percentile)

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  • Snyk IDSNYK-UBUNTU2404-LIBCAP2-15978859
  • published22 Apr 2026
  • disclosed9 Apr 2026

Introduced: 9 Apr 2026

CVE-2026-4878  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

Upgrade Ubuntu:24.04 libcap2 to version 1:2.66-5ubuntu2.4 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libcap2 package and not the libcap2 package as distributed by Ubuntu. See How to fix? for Ubuntu:24.04 relevant fixed versions and status.

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.

References

CVSS Base Scores

version 3.1