CVE-2026-53075
Description
In the Linux kernel, the following vulnerability has been resolved: ppp: require CAP_NET_ADMIN in target netns for unattached ioctls /dev/ppp open is currently authorized against file->f_cred->user_ns, while unattached administrative ioctls operate on current->nsproxy->net_ns. As a result, a local unprivileged user can create a new user namespace with CLONE_NEWUSER, gain CAP_NET_ADMIN only in that new user namespace, and still issue PPPIOCNEWUNIT, PPPIOCATTACH, or PPPIOCATTCHAN against an inherited network namespace. Require CAP_NET_ADMIN in the user namespace that owns the target network namespace before handling unattached PPP administrative ioctls. This preserves normal pppd operation in the network namespace it is actually privileged in, while rejecting the userns-only inherited-netns case.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://git.kernel.org/stable/c/1a8a51ce85075a56a743b6f142606dd2696a391c
- https://git.kernel.org/stable/c/2bb6379416fd19f44c3423a00bfd8626259f6067
- https://git.kernel.org/stable/c/3b2c2157dc2afc5c17cd7238afefca92f1ef330e
- https://git.kernel.org/stable/c/5013be175c7ffd8b39efbc3c9c4db5b10b85fea8
- https://git.kernel.org/stable/c/5080e188c914110034bbc569d5cfa2f06204681d
- https://git.kernel.org/stable/c/67e901e28d177ac9a9bed76d69ce3471e704a89e
- https://git.kernel.org/stable/c/954745d0223e7caec917c0b2d1a889ff56fa6e54
- https://git.kernel.org/stable/c/c9edd90c57ae23692fff6b049fdfa4572a9fd532
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.