CVE-2026-35345
MEDIUMCVE-2026-35345 is a medium-severity (CVSS 5.3) : Time-of-Check Time-of-Use (TOCTOU) Race Condition vulnerability. O3 Security confirms whether CVE-2026-35345 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
A vulnerability in the tail utility of uutils coreutils allows for the exfiltration of sensitive file contents when using the --follow=name option. Unlike GNU tail, the uutils implementation…
Description
A vulnerability in the tail utility of uutils coreutils allows for the exfiltration of sensitive file contents when using the --follow=name option. Unlike GNU tail, the uutils implementation continues to monitor a path after it has been replaced by a symbolic link, subsequently outputting the contents of the link's target. In environments where a privileged user (e.g., root) monitors a log directory, a local attacker with write access to that directory can replace a log file with a symlink to a sensitive system file (such as /etc/shadow), causing tail to disclose the contents of the sensitive file.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-35345 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-35345 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-35345. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-35345 in your dependencies?
O3 detects CVE-2026-35345 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.