CVE-2026-35376 PUBLISHED

uutils coreutils chcon Security Bypass and Mandatory Access Control (MAC) Inconsistency via TOCTOU Race Condition

Assigner: canonical
Reserved: 02.04.2026 Published: 22.04.2026 Updated: 22.04.2026

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the chcon utility of uutils coreutils during recursive operations. The implementation resolves recursive targets using a fresh path lookup (via fts_accpath) rather than binding the traversal and label application to the specific directory state encountered during traversal. Because these operations are not anchored to file descriptors, a local attacker with write access to a directory tree can exploit timing-sensitive rename or symbolic link races to redirect a privileged recursive relabeling operation to unintended files or directories. This vulnerability breaks the hardening expectations for SELinux administration workflows and can lead to the unauthorized modification of security labels on sensitive system objects.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
CVSS Score: 4.5

Product Status

Vendor Uutils
Product coreutils
Versions Default: unaffected
  • affected from 0 to 0.8.0 (excl.)

Credits

  • Zellic finder

References

Problem Types

  • CWE-367: Time-of-Check Time-of-Use (TOCTOU) Race Condition CWE

Impacts

  • CAPEC-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions