chmod: --preserve-root bypassed by any path that resolves to root (e.g. /../)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.3 · CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-35338: 0.18% estimated exploitation activity in the next 30 days; percentile 7.03 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Chmoder::chmod() only compares the literal argument against Path::new("/"), so the --preserve-root guard is bypassed by any path that resolves to root — a symlink to / or simply /../. PoC — recursively chmods the entire filesystem to 000 despite --preserve-root: Impact: --preserve-root is the documented safeguard against destructive recursive operations on /. Bypassing it allows chmod -R to alter permissions across the whole filesystem, causing a complete system breakdown. Recommendation: canonicalize the target path before comparing against root. Remediation: Acknowledged by Canonical; fixed in commit 413055b3. --- Reported by Zellic in the uutils coreutils Program Security Assessment (prepared for Canonical, Jan 20 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242. Finding 3.1. Credit: Zellic.

Published by the source

6 Jul 2026, 17:41 UTC

Last modified by the source

6 Jul 2026, 17:41 UTC

Source last checked

26 Oct 2026, 15:43 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4c7q-4928-8445

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-35338

Advisory: chmod: --preserve-root bypassed by any path that resolves to root (e.g. /../)
IDs: CVE-2026-35338, GHSA-4c7q-4928-8445
Record: https://patchnext.com/advisories/cve-2026-35338 (revision 1, source checked 26 Oct 2026, 15:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: uu_chmod 0.6.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io uu_chmod: affected < 0.6.0; fixed in 0.6.0

## Suggested inspection (read-only)
- crates.io uu_chmod: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on uu_chmod.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4c7q-4928-8445 (GitHub-reviewed advisory GHSA-4c7q-4928-8445 lists affected ranges: crates.io uu_chmod >=0 <0.6.0)

Commands are suggestions: review each one before running it.