CVE-2026-35345 PUBLISHED

uutils coreutils tail Privileged Information Disclosure via Symlink Replacement Race

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

A vulnerability in the tail utility of uutils coreutils allows for the exfiltration of sensitive file contents when using the --follow=name option. Unlike GNU tail, the uutils implementation continues to monitor a path after it has been replaced by a symbolic link, subsequently outputting the contents of the link's target. In environments where a privileged user (e.g., root) monitors a log directory, a local attacker with write access to that directory can replace a log file with a symlink to a sensitive system file (such as /etc/shadow), causing tail to disclose the contents of the sensitive file.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N
CVSS Score: 5.3

Product Status

Vendor Uutils
Product coreutils
Versions Default: affected

Credits

  • Zellic finder

References

Problem Types

  • CWE-367: Time-of-Check Time-of-Use (TOCTOU) Race Condition CWE
  • CWE-59: Improper Link Resolution Before File Access ('Link Following') CWE

Impacts

  • CAPEC-27: Leveraging Race Conditions via Symbolic Links