CyberSecBulletin
CVE-2026-53374NVD status: Modified

Linux: Use of Uninitialized Variable

Published Updated By the CyberSecBulletin desk

CVE-2026-53374 is a high-severity use of uninitialized variable 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 40df11255d71b02e20e70579f1b12b687e396e26, 91fbb5e635c8fb1b49e15c19da06480089ef719f, 8ae8b9e74bab94aab1d79f1688129bcc61c8b29a 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 0.13% 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 40df11255d71b02e20e70579f1b12b687e396e26 or 91fbb5e635c8fb1b49e15c19da06480089ef719f or 8ae8b9e74bab94aab1d79f1688129bcc61c8b29a or b17175d0a375b3ed5e81597dac4983fdb46e478d, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.175 or 6.6.140 or 6.12.90 or 6.18.32, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxd38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, 40df11255d71b02e20e70579f1b12b687e396e26; d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, 91fbb5e635c8fb1b49e15c19da06480089ef719f; d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, 8ae8b9e74bab94aab1d79f1688129bcc61c8b29a; d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, b17175d0a375b3ed5e81597dac4983fdb46e478d; d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, 791941be5da125d9a1b228582bfdc300c05d05b3; d38ceaf99ed015f2a0b9af3499791bd3a3daae21 up to, but not including, e6c2e6c2e1fa066968a16aca1cb66cd1bdde7741; 4.240df11255d71b02e20e70579f1b12b687e396e26, 91fbb5e635c8fb1b49e15c19da06480089ef719f, 8ae8b9e74bab94aab1d79f1688129bcc61c8b29a, b17175d0a375b3ed5e81597dac4983fdb46e478d, 791941be5da125d9a1b228582bfdc300c05d05b3, e6c2e6c2e1fa066968a16aca1cb66cd1bdde7741
LinuxLinux Kernel4.2 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.90; 6.13 up to, but not including, 6.18.32; 6.19 up to, but not including, 7.0.9; 7.16.1.175, 6.6.140, 6.12.90, 6.18.32, 7.0.9

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: drm/amdgpu: zero-initialize GART table on allocation GART TLB is flushed after unmapping but not after mapping. Since amdgpu_bo_create_kernel() does not zero-initialize the buffer, when a single PTE is written the TLB may speculatively load other uninitialized entries from the same cacheline. Those garbage entries can appear valid, and a subsequent write to another PTE in the same cacheline may cause the GPU to use a stale garbage PTE from the TLB. Fix this by calling memset_io() to zero-initialize the GART table with gart_pte_flags immediately after allocation. Using AMDGPU_GEM_CREATE_VRAM_CLEARED, SDMA-based clear will not work since SDMA needs GART to be initialized to work. (cherry picked from commit d9af8263b82b6eaa60c5718e0c6631c5037e4b24)

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

The underlying weakness: Use of Uninitialized Variable

The code uses a variable that has not been initialized, leading to unpredictable or unintended results.

How developers prevent this class of flaw

  • Ensure that critical variables are initialized before first use.
  • Most compilers will complain about the use of uninitialized variables if warnings are turned on.
  • When using a language that does not require explicit declaration of variables, run or compile the software in a mode that reports undeclared or unknown variables. This may indicate the presence of a typographic error in the variable's name.

More Use of Uninitialized Variable vulnerabilities (CWE-457)

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 Variable vulnerabilities

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