Summary
chmod: --preserve-root bypassed by any path that resolves to root (e.g. /../)
Full technical description
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 /../.
if self.recursive && self.preserve_root && file == Path::new("/") {
return Err(ChmodError::PreserveRoot("/".to_string()).into());
}
PoC, recursively chmods the entire filesystem to 000 despite --preserve-root:
chmod -R --preserve-root 000 /../ -v
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.
Impact
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-35338 has a CVSS score of 7.3 (High). The vector is requires local access, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.6.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-35338? CVE-2026-35338 is a high-severity path traversal vulnerability in uu_chmod (rust), affecting versions < 0.6.0. It is fixed in 0.6.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2026-35338? CVE-2026-35338 has a CVSS score of 7.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of uu_chmod are affected by CVE-2026-35338? uu_chmod (rust) versions < 0.6.0 is affected.
- Is there a fix for CVE-2026-35338? Yes. CVE-2026-35338 is fixed in 0.6.0. Upgrade to this version or later.
- Is CVE-2026-35338 exploitable, and should I be worried? Whether CVE-2026-35338 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-35338 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-35338? Upgrade
uu_chmodto 0.6.0 or later.