Vulnerability · Published Apr 22, 2026 · Assigned by canonical
CVE-2026-35355uutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race
Medium 6.3
In plain English
A medium-severity security flaw in coreutils from Uutils. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | rust-coreutils | no fix listed | DEBIAN-CVE-2026-35355 |
| Debian:13 | rust-coreutils | no fix listed | DEBIAN-CVE-2026-35355 |
| Debian:14 | rust-coreutils | 0.6.0-1 | DEBIAN-CVE-2026-35355 |
| Ubuntu:24.04:LTS | rust-coreutils | no fix listed | UBUNTU-CVE-2026-35355 |
| Ubuntu:25.10 | rust-coreutils | no fix listed | UBUNTU-CVE-2026-35355 |
Affected products (as reported)
Weakness: CWE-367 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
References
- https://github.com/uutils/coreutils/pull/10067 issue-tracking, patch
- https://github.com/uutils/coreutils/releases/tag/0.6.0 vendor-advisory