{"id":"CVE-2026-35355","aliases":["GHSA-239g-2685-54x3"],"url":"https://o3.security/vulnerability/CVE-2026-35355","summary":"uutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race","details":"`copy_file` in `install/src/install.rs` removes the destination then recreates it by pathname via `File::create` / `fs::copy` without `O_EXCL`/`create_new`. Between the unlink and the recreate, a local attacker with write access to the destination directory can drop in a symlink and redirect the write.\n\n**Impact:** when `install` runs privileged into an attacker-writable directory (staging/build paths), the race allows redirecting writes to arbitrary files and overwriting sensitive system files (`/etc/passwd`, `/etc/shadow`). Recommendation: create atomically with `create_new`/`O_EXCL` and copy via the opened fd rather than reopening by path.\n\n**Remediation:** Acknowledged by Canonical; fixed in commit b5bbabc1.\n\n---\n_Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.50. Credit: Zellic._","published":"2026-04-22T16:08:14.960Z","modified":"2026-08-12T03:51:48.979672147Z","cvss":{"score":6.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H"},"epss":{"score":0.00118,"percentile":0.01929,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"uu_install","fixedVersion":"0.6.0"}],"fix":{"url":"https://github.com/uutils/coreutils/pull/10067","label":"uutils/coreutils#10067"},"references":[{"type":"WEB","url":"https://github.com/uutils"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35355.json"},{"type":"ADVISORY","url":"https://github.com/uutils/coreutils/releases/tag/0.6.0"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35355"},{"type":"FIX","url":"https://github.com/uutils/coreutils/pull/10067"},{"type":"PACKAGE","url":"https://github.com/uutils/coreutils"},{"type":"WEB","url":"https://github.com/uutils/coreutils/security/advisories/GHSA-239g-2685-54x3"},{"type":"WEB","url":"https://github.com/uutils/coreutils/commit/b5bbabc18a1121908848d836f869a4e98eb63886"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:48.979672147Z"}}