CVE-2026-35340
MEDIUMA flaw in the ChownExecutor used by uutils coreutils chown and chgrp causes the utilities to return an incorrect exit code during recursive operations. The final exit code is determined…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
A flaw in the ChownExecutor used by uutils coreutils chown and chgrp causes the utilities to return an incorrect exit code during recursive operations. The final exit code is determined only by the last file processed. If the last operation succeeds, the command returns 0 even if earlier ownership or group changes failed due to permission errors. This can lead to security misconfigurations where administrative scripts incorrectly assume that ownership has been successfully transferred across a directory tree.
Affected Products
coreutilsuutilsDetection & mitigation playbook
Vendor / applianceDetect
Inventory every uutils coreutils deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the uutils coreutils security patch or hotfix for CVE-2026-35340 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-35340 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-35340. 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-2026-35340 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-35340 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.