Local privilege escalation via chmod-before-chown ordering
Published Sep 18, 2026 · Updated Sep 18, 2026
Improper permission preservation in the install utility of uutils coreutils 0.0.18 through 0.9.0 allows local users to execute files with effective UID 0. set_ownership_and_permissions applies the requested setuid or setgid mode before chown or chgrp and leaves that mode intact if ownership finalization fails. Exploitation requires a reachable attacker-influenced destination, failed ownership change, permitted setuid execution, and no NoNewPrivs restriction.
Summary
What happened
Improper permission preservation in the install utility of uutils coreutils 0.0.18 through 0.9.0 allows local users to execute files with effective UID 0. set_ownership_and_permissions applies the requested setuid or setgid mode before chown or chgrp and leaves that mode intact if ownership finalization fails. Exploitation requires a reachable attacker-influenced destination, failed ownership change, permitted setuid execution, and no NoNewPrivs restriction.
The record
- CVE
- CVE-2026-93658
- Published
- Sep 18, 2026
- Updated
- Sep 18, 2026
- Vendor
- uutils
- Product
- coreutils
- Classifications
- CWE-281, T1548.001
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 18, 2026CVE publishedPublication date reported by the CVE source.
- Sep 18, 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=0.0.18 <0.10.0
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.
Activity data is delayed. The latest report is Sep 28, 2026.
Public exploit references
- poc_install_root_owned_setuid.shproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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