{"id":"CVE-2026-35355","aliases":["DEBIAN-CVE-2026-35355","EUVD-2026-24992","GHSA-239g-2685-54x3","GHSA-v24v-f45g-w7jf","UBUNTU-CVE-2026-35355"],"status":"published","title":"uutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","severity":{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00118,"percentile":0.01716,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-367","CWE-59"],"published":"2026-04-22T16:08:14Z","modified":"2026-10-28T02:30:41Z","fixes":[{"ecosystem":"crates.io","package":"uu_install","fixed_in":["0.6.0"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"rust-coreutils","fixed_in":["0.6.0-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"uu_install","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"rust-coreutils","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.17-2","0.0.17-3","0.0.17-4","0.0.17-5","0.0.17-6","0.0.19-1","0.0.19-2","0.0.19-3","0.0.20-1","0.0.21-1","0.0.22-1","0.0.23-1","0.0.23-2","0.0.23-3","0.0.24-1","0.0.24-2","0.0.26-1","0.0.26-2","0.0.26-3","0.0.26-4","0.0.26-5","0.0.27-1","0.0.27-2","0.0.27-3","0.0.30-1","0.0.30-2","0.0.30-3","0.0.30-3~exp1","0.0.30-4","0.10.0-1","0.11.0-1","0.11.0-2","0.12.0-1","0.6.0-1","0.7.0-1","0.8.0-1","0.8.0-2","0.8.0-3","0.8.0-4","0.8.0-5","0.8.0-6","0.9.0-1","0.9.0-2","0.9.0-3"]},{"source":"osv","ecosystem":"Debian:13","package":"rust-coreutils","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.30-2","0.0.30-3","0.0.30-3~exp1","0.0.30-4","0.10.0-1","0.11.0-1","0.11.0-2","0.12.0-1","0.6.0-1","0.7.0-1","0.8.0-1","0.8.0-2","0.8.0-3","0.8.0-4","0.8.0-5","0.8.0-6","0.9.0-1","0.9.0-2","0.9.0-3"]},{"source":"osv","ecosystem":"Debian:14","package":"rust-coreutils","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.0-1"}]}],"versions":["0.0.30-2","0.0.30-3","0.0.30-3~exp1","0.0.30-4"]},{"source":"osv","ecosystem":"crates.io","package":"uu_install","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.6.0"}]}]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"rust-coreutils","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.20-1","0.0.22-1","0.0.23-1","0.0.23-2","0.0.23-3","0.0.24-1","0.0.24-2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"rust-coreutils","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.30-1","0.0.30-2","0.0.30-2ubuntu2","0.1.0-0ubuntu1","0.1.0+git20250711.2ba3a33-0ubuntu1","0.1.0+git20250711.2ba3a33-0ubuntu2","0.1.0+git20250711.2ba3a33-0ubuntu3","0.1.0+git20250711.2ba3a33-0ubuntu4","0.1.0+git20250801.cf79675-0ubuntu1","0.1.0+git20250813.4af2a84-0ubuntu2","0.1.0+git20250813.4af2a84-0ubuntu4","0.1.0+git20250813.4af2a84-0ubuntu6","0.1.0+git20250813.4af2a84-0ubuntu7","0.2.2-0ubuntu1","0.2.2-0ubuntu2","0.2.2-0ubuntu2.1"]}],"products":[{"vendor":"uutils","product":"coreutils"}],"references":[{"url":"https://github.com/uutils/coreutils/pull/10067","tags":["issue-tracking","patch","exploit","Exploit","Issue Tracking","Patch","fix","web","report"]},{"url":"https://github.com/uutils/coreutils/releases/tag/0.6.0","tags":["vendor-advisory","Release Notes","advisory","web"]},{"url":"https://github.com/uutils/coreutils/security/advisories/GHSA-239g-2685-54x3","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35355","tags":["advisory"]},{"url":"https://github.com/uutils/coreutils/commit/b5bbabc18a1121908848d836f869a4e98eb63886","tags":["web"]},{"url":"https://github.com/advisories/GHSA-239g-2685-54x3"},{"url":"https://github.com/advisories/GHSA-v24v-f45g-w7jf"},{"url":"https://github.com/uutils","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35355.json","tags":["advisory"]},{"url":"https://github.com/uutils/coreutils","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-35355","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-35355","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-35355","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-35355","title":"uutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"published","published":"2026-04-22T16:08:14.96Z","modified":"2026-04-22T18:01:47.122Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:20:05.505362Z"}],"euvd":[{"id":"EUVD-2026-24992","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"published","published":"2026-04-22T16:08:14Z","modified":"2026-04-22T18:01:47Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"updated_at":"2026-11-02T19:24:19.81608Z"}],"ghsa":[{"id":"GHSA-239g-2685-54x3","title":"install: TOCTOU symlink race (unlink-then-create without O_EXCL) allows arbitrary file overwrite","description":"`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._","status":"published","published":"2026-07-06T19:54:08Z","modified":"2026-07-06T19:54:09Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"cwes":["CWE-59","CWE-367"],"updated_at":"2026-11-02T14:40:39.314643Z"},{"id":"GHSA-v24v-f45g-w7jf","title":"Duplicate Advisory: uutils coreutils has a Time-of-Check to Time-of-Use (TOCTOU) race condition","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-239g-2685-54x3. This link is maintained to preserve external references.\n\n### Original Description\nThe install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"withdrawn","published":"2026-04-22T18:31:45Z","modified":"2026-07-06T19:54:01Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:40:39.314643Z"}],"nvd":[{"id":"CVE-2026-35355","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"published","published":"2026-04-22T17:16:37.993Z","modified":"2026-10-26T21:10:00.17Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T14:12:15.867234Z"}],"osv":[{"id":"CVE-2026-35355","title":"uutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"published","published":"2026-04-22T16:08:14.96Z","modified":"2026-10-28T02:30:41.788129017Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T15:45:02.673625Z"},{"id":"DEBIAN-CVE-2026-35355","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"published","published":"2026-04-22T17:16:37.993Z","modified":"2026-10-27T09:47:35.517006144Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:54.587575Z"},{"id":"GHSA-239g-2685-54x3","title":"install: TOCTOU symlink race (unlink-then-create without O_EXCL) allows arbitrary file overwrite","description":"`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._","status":"published","published":"2026-07-06T19:54:08Z","modified":"2026-07-06T20:11:15.72523Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"cwes":["CWE-367","CWE-59"],"updated_at":"2026-11-02T15:46:33.520522Z"},{"id":"GHSA-v24v-f45g-w7jf","title":"Duplicate Advisory: uutils coreutils has a Time-of-Check to Time-of-Use (TOCTOU) race condition","description":"### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-239g-2685-54x3. This link is maintained to preserve external references.\n\n### Original Description\nThe install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"withdrawn","published":"2026-04-22T18:31:45Z","modified":"2026-09-10T03:50:44.788517644Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"cwes":["CWE-367"],"updated_at":"2026-11-02T15:46:56.639206Z"},{"id":"UBUNTU-CVE-2026-35355","description":"The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.","status":"published","published":"2026-04-22T17:16:00Z","modified":"2026-05-14T14:41:21.607123Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H","level":"medium"}],"updated_at":"2026-11-02T16:56:16.686388Z"}]}}