CVE-2026-53075
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.25% probability · 16th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/1a8a51ce85075a56a743b6f142606dd2696a391cPatch
- https://git.kernel.org/stable/c/2bb6379416fd19f44c3423a00bfd8626259f6067Patch
- https://git.kernel.org/stable/c/3b2c2157dc2afc5c17cd7238afefca92f1ef330ePatch
- https://git.kernel.org/stable/c/5013be175c7ffd8b39efbc3c9c4db5b10b85fea8Patch
- https://git.kernel.org/stable/c/5080e188c914110034bbc569d5cfa2f06204681dPatch
- https://git.kernel.org/stable/c/67e901e28d177ac9a9bed76d69ce3471e704a89ePatch
- https://git.kernel.org/stable/c/954745d0223e7caec917c0b2d1a889ff56fa6e54Patch
- https://git.kernel.org/stable/c/c9edd90c57ae23692fff6b049fdfa4572a9fd532Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.