Arbitrary file overwrite via symlink TOCTOU race
Published Apr 22, 2026 · Updated Apr 22, 2026
TOCTOU race in uutils coreutils install before 0.6.0 allows local users to overwrite arbitrary files through a symlink swap. The copy_file function removes the destination and recreates it by pathname with File::create or fs::copy, without exclusive creation. Exploitation requires write access to the destination directory and winning the unlink-to-create race; privileged execution redirects the resulting write.
Summary
What happened
TOCTOU race in uutils coreutils install before 0.6.0 allows local users to overwrite arbitrary files through a symlink swap. The copy_file function removes the destination and recreates it by pathname with File::create or fs::copy, without exclusive creation. Exploitation requires write access to the destination directory and winning the unlink-to-create race; privileged execution redirects the resulting write.
The record
- CVE
- CVE-2026-35355
- Published
- Apr 22, 2026
- Updated
- Apr 22, 2026
- Vendor
- uutils
- Product
- coreutils
- Classifications
- CWE-59, CWE-367
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Apr 22, 2026CVE publishedPublication date reported by the CVE source.
- Apr 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <0.6.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream symlink-race reproduction stepsproof of concept · unverified
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Technologies
Your stack
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Your stack
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