{"id":"CVE-2026-35338","aliases":["GHSA-4c7q-4928-8445"],"url":"https://o3.security/vulnerability/CVE-2026-35338","summary":"uutils coreutils chmod Path Traversal Bypass of --preserve-root","details":"`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 `/../`.\n\n```\nif self.recursive && self.preserve_root && file == Path::new(\"/\") {\n    return Err(ChmodError::PreserveRoot(\"/\".to_string()).into());\n}\n```\n\n**PoC** — recursively chmods the entire filesystem to `000` despite `--preserve-root`:\n\n```\nchmod -R --preserve-root 000 /../ -v\n```\n\n**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.\n\n**Remediation:** Acknowledged by Canonical; fixed in commit 413055b3.\n\n---\n_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":"2026-04-22T16:07:31.316Z","modified":"2026-08-12T03:51:30.066116354Z","cvss":{"score":7.3,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H"},"epss":{"score":0.00175,"percentile":0.07299,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"uu_chmod","fixedVersion":"0.6.0"}],"fix":{"url":"https://github.com/uutils/coreutils/pull/10033","label":"uutils/coreutils#10033"},"references":[{"type":"WEB","url":"https://github.com/uutils"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35338.json"},{"type":"ADVISORY","url":"https://github.com/uutils/coreutils/releases/tag/0.6.0"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35338"},{"type":"FIX","url":"https://github.com/uutils/coreutils/pull/10033"},{"type":"PACKAGE","url":"https://github.com/uutils/coreutils"},{"type":"WEB","url":"https://github.com/uutils/coreutils/security/advisories/GHSA-4c7q-4928-8445"},{"type":"WEB","url":"https://github.com/uutils/coreutils/commit/413055b378fa6fe2299c5e5f538c8e6e841ab810"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:30.066116354Z"}}