CVE Catalog

CVE-2026-53075

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.24%

15th percentile - higher than 15% of all known CVEs

Summary

In the Linux kernel, the ppp driver lacks a requirement for CAP_NET_ADMIN in the target network namespace for unattached ioctls. A local unprivileged user can create a new user namespace, gain CAP_NET_ADMIN only in that namespace, and then issue PPPIOCNEWUNIT, PPPIOCATTACH, or PPPIOCATTCHAN against an inherited network namespace.

Risk Assessment

An attacker could gain unauthorized access to PPP interfaces in the system, potentially leading to privilege escalation or network integrity compromise.

Recommendation

Update the Linux kernel to a version that includes the fix requiring CAP_NET_ADMIN in the appropriate user namespace.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS