CVE-2026-35359
MEDIUMCVE-2026-35359 is a medium-severity (CVSS 4.7) : Time-of-Check Time-of-Use (TOCTOU) Race Condition vulnerability. O3 Security confirms whether CVE-2026-35359 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability in the cp utility of uutils coreutils allows an attacker to bypass no-dereference intent. The utility checks if a source path is…
Description
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability in the cp utility of uutils coreutils allows an attacker to bypass no-dereference intent. The utility checks if a source path is a symbolic link using path-based metadata but subsequently opens it without the O_NOFOLLOW flag. An attacker with concurrent write access can swap a regular file for a symbolic link during this window, causing a privileged cp process to copy the contents of arbitrary sensitive files into a destination controlled by the attacker.
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-2026-35359 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-2026-35359 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-2026-35359. 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-2026-35359 in your dependencies?
O3 detects CVE-2026-35359 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.