{"id":"GHSA-239g-2685-54x3","summary":"install: TOCTOU symlink race (unlink-then-create without O_EXCL) allows arbitrary file overwrite","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._","aliases":["CVE-2026-35355"],"modified":"2026-07-06T20:11:15.725230Z","published":"2026-07-06T19:54:08Z","database_specific":{"cwe_ids":["CWE-367","CWE-59"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-07-06T19:54:08Z","nvd_published_at":null},"references":[{"type":"WEB","url":"https://github.com/uutils/coreutils/security/advisories/GHSA-239g-2685-54x3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35355"},{"type":"WEB","url":"https://github.com/uutils/coreutils/pull/10067"},{"type":"WEB","url":"https://github.com/uutils/coreutils/commit/b5bbabc18a1121908848d836f869a4e98eb63886"},{"type":"PACKAGE","url":"https://github.com/uutils/coreutils"},{"type":"WEB","url":"https://github.com/uutils/coreutils/releases/tag/0.6.0"}],"affected":[{"package":{"name":"uu_install","ecosystem":"crates.io","purl":"pkg:cargo/uu_install"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.6.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-239g-2685-54x3/GHSA-239g-2685-54x3.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H"}]}