CyberSecBulletin
CVE-2026-52957NVD status: Modified

Linux: NULL Pointer Dereference

Published Updated By the CyberSecBulletin desk

CVE-2026-52957 is a high-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions d55ffad8d422b5d1cc44dad32bd3d25f4471cd9f, 301286c0ccd37d66b0e40786fd35a4f19cdbd88a, 7169f326a23d0f547fcd90e68b72fd387622e126 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 0.52% 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 d55ffad8d422b5d1cc44dad32bd3d25f4471cd9f or 301286c0ccd37d66b0e40786fd35a4f19cdbd88a or 7169f326a23d0f547fcd90e68b72fd387622e126 or d7a65a34d2453f8cd3e0cc0e1319740af7e24276, 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.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxc7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, d55ffad8d422b5d1cc44dad32bd3d25f4471cd9f; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, 301286c0ccd37d66b0e40786fd35a4f19cdbd88a; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, 7169f326a23d0f547fcd90e68b72fd387622e126; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, d7a65a34d2453f8cd3e0cc0e1319740af7e24276; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, 312ec973efac0efb9b9ed64214235910e9ecbaa8; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, f2f95e6d4b97e70bb876139b0583fc8079983f85; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, a20e16ebfe2fa65348eb4b2dc7deac330ce03e9c; c7ed1a4bf4b446317eefa0f4916d94b1f6d3ada5 up to, but not including, 28b0a2ab8c82d0bbdeb8013029c67c978ce6e4bf; and 1 more rangesd55ffad8d422b5d1cc44dad32bd3d25f4471cd9f, 301286c0ccd37d66b0e40786fd35a4f19cdbd88a, 7169f326a23d0f547fcd90e68b72fd387622e126, d7a65a34d2453f8cd3e0cc0e1319740af7e24276, 312ec973efac0efb9b9ed64214235910e9ecbaa8, f2f95e6d4b97e70bb876139b0583fc8079983f85
LinuxLinux Kernel4.13.1 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, 7.0.10; 4.13; and 1 more ranges5.10.258, 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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Official description

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential null-ptr-deref in decode_choose_args() A message of type CEPH_MSG_OSD_MAP contains an OSD map that itself contains a CRUSH map. When decoding this CRUSH map in crush_decode(), an array of max_buckets CRUSH buckets is decoded, where some indices may not refer to actual buckets and are therefore set to NULL. The received CRUSH map may optionally contain choose_args that get decoded in decode_choose_args(). When decoding a crush_choose_arg_map, a series of choose_args for different buckets is decoded, with the bucket_index being read from the incoming message. It is only checked that the bucket index does not exceed max_buckets, but not that it doesn't point to an index with a NULL bucket. If a (potentially corrupted) message contains a crush_choose_arg_map including such a bucket_index, a null pointer dereference may occur in the subsequent processing when attempting to access the bucket with the given index. This patch fixes the issue by extending the affected check. Now, it is only attempted to access the bucket if it is not NULL.

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

The underlying weakness: NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

How developers prevent this class of flaw

  • For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
  • Select a programming language that is not susceptible to these issues.
  • Check the results of all functions that return a value and verify that the value is non-null before acting upon it.

More NULL Pointer Dereference vulnerabilities (CWE-476)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent NULL Pointer Dereference vulnerabilities

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