CyberSecBulletin
CVE-2026-31414NVD status: Modified

Linux: NULL Pointer Dereference

Published Updated By the CyberSecBulletin desk

CVE-2026-31414 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 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781, e7ccaa0a62a8ff2be5d521299ce79390c318d306, 4bd1b3d839172724b33d8d02c5a4ff6a1c775417 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 0.58% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781 or e7ccaa0a62a8ff2be5d521299ce79390c318d306 or 4bd1b3d839172724b33d8d02c5a4ff6a1c775417 or b53294bff19e56ada2f230ceb8b1ffde61cc3817, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.168 or 6.6.134 or 6.12.81 or 6.18.22, 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
LinuxLinuxea781f197d6a835cbb93a0bf88ee1696296ed8aa up to, but not including, 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781; ea781f197d6a835cbb93a0bf88ee1696296ed8aa up to, but not including, e7ccaa0a62a8ff2be5d521299ce79390c318d306; ea781f197d6a835cbb93a0bf88ee1696296ed8aa up to, but not including, 4bd1b3d839172724b33d8d02c5a4ff6a1c775417; ea781f197d6a835cbb93a0bf88ee1696296ed8aa up to, but not including, b53294bff19e56ada2f230ceb8b1ffde61cc3817; ea781f197d6a835cbb93a0bf88ee1696296ed8aa up to, but not including, 3dfd3f7712b5a800f2ba632179e9b738076a51f0; ea781f197d6a835cbb93a0bf88ee1696296ed8aa up to, but not including, f01794106042ee27e54af6fdf5b319a2fe3df94d; 2.6.30847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781, e7ccaa0a62a8ff2be5d521299ce79390c318d306, 4bd1b3d839172724b33d8d02c5a4ff6a1c775417, b53294bff19e56ada2f230ceb8b1ffde61cc3817, 3dfd3f7712b5a800f2ba632179e9b738076a51f0, f01794106042ee27e54af6fdf5b319a2fe3df94d
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)V3.1.6 and later; V3.1.5 and later; V3.1.7 and laterNot stated
LinuxLinux Kernel2.6.30 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.134; 6.7 up to, but not including, 6.12.81; 6.13 up to, but not including, 6.18.22; 6.19 up to, but not including, 6.19.12; 7.06.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: use expect->helper Use expect->helper in ctnetlink and /proc to dump the helper name. Using nfct_help() without holding a reference to the master conntrack is unsafe. Use exp->master->helper in ctnetlink path if userspace does not provide an explicit helper when creating an expectation to retain the existing behaviour. The ctnetlink expectation path holds the reference on the master conntrack and nf_conntrack_expect lock and the nfnetlink glue path refers to the master ct that is attached to the skb.

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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