CVE-2026-53075 Details
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.
A vulnerability in the Linux kernel's PPP (Point-to-Point Protocol) implementation allows local unprivileged users to escalate privileges by manipulating user namespaces and network namespaces. The issue arises because unattached administrative IOCTLs (Input/Output Control commands) can be directed to an inherited network namespace without proper authorization. By creating a new user namespace and gaining CAP_NET_ADMIN privileges, a user can issue certain PPP IOCTL commands that should require administrative rights in the target network namespace.
Users should be advised to update to the patched version of the Linux kernel where this vulnerability has been addressed. Instructions for updating the kernel can be found in the official Linux documentation or through the package management system of the respective Linux distribution.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/1a8a51ce85075a56a743b6f142606dd2696a391c | kernel.org | Patch |
| https://git.kernel.org/stable/c/2bb6379416fd19f44c3423a00bfd8626259f6067 | kernel.org | Patch |
| https://git.kernel.org/stable/c/3b2c2157dc2afc5c17cd7238afefca92f1ef330e | kernel.org | Patch |
| https://git.kernel.org/stable/c/5013be175c7ffd8b39efbc3c9c4db5b10b85fea8 | kernel.org | Patch |
| https://git.kernel.org/stable/c/5080e188c914110034bbc569d5cfa2f06204681d | kernel.org | Patch |
| https://git.kernel.org/stable/c/67e901e28d177ac9a9bed76d69ce3471e704a89e | kernel.org | Patch |
| https://git.kernel.org/stable/c/954745d0223e7caec917c0b2d1a889ff56fa6e54 | kernel.org | Patch |
| https://git.kernel.org/stable/c/c9edd90c57ae23692fff6b049fdfa4572a9fd532 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| NVD-CWE-noinfo | Insufficient Information to Classify Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 2.6.30, < 5.10.258 >= 5.11, < 5.15.209 >= 5.16, < 6.1.175 >= 6.2, < 6.6.141 >= 6.7, < 6.12.91 >= 6.13, < 6.18.33 >= 6.19, < 7.0.10 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 21, 2026 | Initial Analysis | [email protected] |
| Jun 28, 2026 | CVE Modified | kernel.org |
| Jun 24, 2026 | New CVE Received | kernel.org |