CyberSecBulletin
CVE-2026-31693NVD status: Modified

Linux: Use of Uninitialized Resource

Published Updated By the CyberSecBulletin desk

CVE-2026-31693 is a high-severity use of uninitialized resource vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 c854ab481ece4b3e5f4c2e8b22824f015ff874a5, 1d731e512134495e0ef490ade0e4d91dc0d515ec, 7c9ce68192eef14c777cb6ce17155d2eb2431aea 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 0.17% 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 c854ab481ece4b3e5f4c2e8b22824f015ff874a5 or 1d731e512134495e0ef490ade0e4d91dc0d515ec or 7c9ce68192eef14c777cb6ce17155d2eb2431aea or c99e160938b627f6f28edee930e8abc157e84386, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.128 or 6.12.75 or 6.18.16 or 6.19.6, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux433042a91f9373241307725b52de573933ffedbf up to, but not including, c854ab481ece4b3e5f4c2e8b22824f015ff874a5; 4f1fffa2376922f3d1d506e49c0fd445b023a28e up to, but not including, 1d731e512134495e0ef490ade0e4d91dc0d515ec; 4f1fffa2376922f3d1d506e49c0fd445b023a28e up to, but not including, 7c9ce68192eef14c777cb6ce17155d2eb2431aea; 4f1fffa2376922f3d1d506e49c0fd445b023a28e up to, but not including, c99e160938b627f6f28edee930e8abc157e84386; 4f1fffa2376922f3d1d506e49c0fd445b023a28e up to, but not including, 14f66f44646333d2bfd7ece36585874fd72f8286; 6.6.32 up to, but not including, 6.6.128; 6.8c854ab481ece4b3e5f4c2e8b22824f015ff874a5, 1d731e512134495e0ef490ade0e4d91dc0d515ec, 7c9ce68192eef14c777cb6ce17155d2eb2431aea, c99e160938b627f6f28edee930e8abc157e84386, 14f66f44646333d2bfd7ece36585874fd72f8286, 6.6.128
LinuxLinux Kernel6.6.32 up to, but not including, 6.6.128; 6.8.1 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.16; 6.19 up to, but not including, 6.19.6; 6.86.6.128, 6.12.75, 6.18.16, 6.19.6

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
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:L/AC:L/PR:L/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: cifs: some missing initializations on replay In several places in the code, we have a label to signify the start of the code where a request can be replayed if necessary. However, some of these places were missing the necessary reinitializations of certain local variables before replay. This change makes sure that these variables get initialized after the label.

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

The underlying weakness: Use of Uninitialized Resource

The product uses or accesses a resource that has not been initialized.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Use of Uninitialized Resource vulnerabilities (CWE-908)

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 Use of Uninitialized Resource vulnerabilities

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