CVE-2026-25740 Privilege escalation to the `CAP_NET_RAW` capability via the `programs.captive-browser` NixOS module
Enabling the captive-browser module allows any user to execute commands with CAP_NET_RAW privileges, requiring an upgrade to patched NixOS versions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25740?
CVE-2026-25740 is a medium-severity vulnerability in NixOS nixpkgs, published on 9 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
captive browser, a dedicated Chrome instance to log into captive portals without messing with DNS settings. In 25.05 and earlier, when programs.captive-browser is enabled, any user of the system can run arbitrary commands with the CAP_NET_RAW capability (binding to privileged ports, spoofing localhost traffic from privileged services...). This vulnerability is fixed in 25.11 and 26.05.
Weakness: CWE-250
Which versions are affected by CVE-2026-25740?
How do I fix CVE-2026-25740?
No fix has been published for CVE-2026-25740 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25740 being exploited?
There is no known exploitation of CVE-2026-25740 in the wild and no public exploit code.
Sources
Also known as GHSA-wc3r-c66x-8xmc.