CyberSecBulletin
CVE-2026-46195NVD status: Modified

Linux: NULL Pointer Dereference

Published Updated By the CyberSecBulletin desk

CVE-2026-46195 is a critical-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 9.8 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 5de2665e913a10ad70aaeecf736b97276e83d995, f9dc3be8f403c1216df73e57221f44b045e7ee0b, ba7f71b6161c0943dafc367565e5843d16b7d505 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 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 5de2665e913a10ad70aaeecf736b97276e83d995 or f9dc3be8f403c1216df73e57221f44b045e7ee0b or ba7f71b6161c0943dafc367565e5843d16b7d505 or 3b1ddba19e77ee35241cd27f16dc3e8d14e08db7, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.140 or 6.12.88 or 6.18.30 or 7.0.7, 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
LinuxLinuxbc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, 5de2665e913a10ad70aaeecf736b97276e83d995; bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, f9dc3be8f403c1216df73e57221f44b045e7ee0b; bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, ba7f71b6161c0943dafc367565e5843d16b7d505; bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, 3b1ddba19e77ee35241cd27f16dc3e8d14e08db7; bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, c688f3ed73d31943334ad2139cb02ec49664322a; bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, 8bd07e417b6bda67e317920584e48cb6ee442a8a; bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 up to, but not including, f98b48151cc502ada59d9778f0112d21f2586ca3; 5.125de2665e913a10ad70aaeecf736b97276e83d995, f9dc3be8f403c1216df73e57221f44b045e7ee0b, ba7f71b6161c0943dafc367565e5843d16b7d505, 3b1ddba19e77ee35241cd27f16dc3e8d14e08db7, c688f3ed73d31943334ad2139cb02ec49664322a, 8bd07e417b6bda67e317920584e48cb6ee442a8a
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7Not specified in the recordNot stated
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel5.12 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.7; 7.16.6.140, 6.12.88, 6.18.30, 7.0.7

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

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalCNA
CVSS 3.17.5HighCNA

Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building DACL pointers parse_sec_desc(), build_sec_desc(), and the chown path in id_mode_to_cifs_acl() all add the server-supplied dacloffset to pntsd before proving a DACL header fits inside the returned security descriptor. On 32-bit builds a malicious server can return dacloffset near U32_MAX, wrap the derived DACL pointer below end_of_acl, and then slip past the later pointer-based bounds checks. build_sec_desc() and id_mode_to_cifs_acl() can then dereference DACL fields from the wrapped pointer in the chmod/chown rewrite paths. Validate dacloffset numerically before building any DACL pointer and reuse the same helper at the three DACL entry points.

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: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent NULL Pointer Dereference vulnerabilities

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