CyberSecBulletin
CVE-2026-53075NVD status: Modified

Linux: Incorrect Authorization

Published Updated By the CyberSecBulletin desk

CVE-2026-53075 is a high-severity incorrect authorization vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions c9edd90c57ae23692fff6b049fdfa4572a9fd532, 5080e188c914110034bbc569d5cfa2f06204681d, 67e901e28d177ac9a9bed76d69ce3471e704a89e as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to c9edd90c57ae23692fff6b049fdfa4572a9fd532 or 5080e188c914110034bbc569d5cfa2f06204681d or 67e901e28d177ac9a9bed76d69ce3471e704a89e or 954745d0223e7caec917c0b2d1a889ff56fa6e54, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.141, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, c9edd90c57ae23692fff6b049fdfa4572a9fd532; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 5080e188c914110034bbc569d5cfa2f06204681d; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 67e901e28d177ac9a9bed76d69ce3471e704a89e; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 954745d0223e7caec917c0b2d1a889ff56fa6e54; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 3b2c2157dc2afc5c17cd7238afefca92f1ef330e; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 5013be175c7ffd8b39efbc3c9c4db5b10b85fea8; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 1a8a51ce85075a56a743b6f142606dd2696a391c; 273ec51dd7ceaa76e038875d85061ec856d8905e up to, but not including, 2bb6379416fd19f44c3423a00bfd8626259f6067; and 1 more rangesc9edd90c57ae23692fff6b049fdfa4572a9fd532, 5080e188c914110034bbc569d5cfa2f06204681d, 67e901e28d177ac9a9bed76d69ce3471e704a89e, 954745d0223e7caec917c0b2d1a889ff56fa6e54, 3b2c2157dc2afc5c17cd7238afefca92f1ef330e, 5013be175c7ffd8b39efbc3c9c4db5b10b85fea8
LinuxLinux Kernel2.6.30 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.105.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA.

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

How developers prevent this class of flaw

  • Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.

More Incorrect Authorization vulnerabilities (CWE-863)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Incorrect Authorization vulnerabilities

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