Vulnerability in Uutils Coreutils
CVE-2026-35374
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the split utility of uutils coreutils. The program attempts to prevent data loss by checking for identity between input and output files using their file paths before initiating the split operation. However, the utility subsequently opens the output file with truncation after this path-based validation is complete. A local attacker with write access to the directory can exploit this race window by manipulating mutable path components (e.g., swapping a path with a symbolic link). This can cause split to truncate and write to an unintended target file, potentially including the input file itself or other sensitive files accessible to the process, leading to permanent data loss.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
EPSS: 0.001 (0.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H.
Affected products
Weakness classification (CWE)
References
- security@ubuntu.com (issue-tracking, patch, Issue Tracking)
Frequently asked questions
- What is CVE-2026-35374?
- CVE-2026-35374 is a medium-severity vulnerability in Uutils Coreutils, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 6.3/10. Published 2026-04-22.
- How severe is CVE-2026-35374?
- Medium severity. CVSS v3 base score is 6.3 out of 10.