CVE-2026-35359 PUBLISHED

uutils coreutils cp Information Disclosure via Time-of-Check to Time-of-Use Symlink Swap

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

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability in the cp utility of uutils coreutils allows an attacker to bypass no-dereference intent. The utility checks if a source path is a symbolic link using path-based metadata but subsequently opens it without the O_NOFOLLOW flag. An attacker with concurrent write access can swap a regular file for a symbolic link during this window, causing a privileged cp process to copy the contents of arbitrary sensitive files into a destination controlled by the attacker.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS Score: 4.7

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-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
  • CAPEC-132: Symlink Attack