CyberSecBulletin
CVE-2026-43172NVD status: Modified

Linux: Improper Validation of Array Index

Published Updated By the CyberSecBulletin desk

CVE-2026-43172 is a high-severity improper validation of array index vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 5cc021586420c5e13acc65da5bf73edd451e2c3e, b23c7cd616a6a113363be707b7b9e4bc41b18a07, 1d49a42717bdc8de77eabeb5b7d3e88d141ffea9 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 0.33% 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 5cc021586420c5e13acc65da5bf73edd451e2c3e or b23c7cd616a6a113363be707b7b9e4bc41b18a07 or 1d49a42717bdc8de77eabeb5b7d3e88d141ffea9 or 2b4b1510aaaf5b9fb57327ecffc20c055f61f205, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.18.16 or 6.19.6, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxebfa7f8ae155c9a0bb2e4038d6b5d8b14881c424 up to, but not including, 5cc021586420c5e13acc65da5bf73edd451e2c3e; ebfa7f8ae155c9a0bb2e4038d6b5d8b14881c424 up to, but not including, b23c7cd616a6a113363be707b7b9e4bc41b18a07; ebfa7f8ae155c9a0bb2e4038d6b5d8b14881c424 up to, but not including, 1d49a42717bdc8de77eabeb5b7d3e88d141ffea9; ebfa7f8ae155c9a0bb2e4038d6b5d8b14881c424 up to, but not including, 2b4b1510aaaf5b9fb57327ecffc20c055f61f205; ebfa7f8ae155c9a0bb2e4038d6b5d8b14881c424 up to, but not including, 58192b9ce09b0f0f86e2036683bd542130b91a98; 5.85cc021586420c5e13acc65da5bf73edd451e2c3e, b23c7cd616a6a113363be707b7b9e4bc41b18a07, 1d49a42717bdc8de77eabeb5b7d3e88d141ffea9, 2b4b1510aaaf5b9fb57327ecffc20c055f61f205, 58192b9ce09b0f0f86e2036683bd542130b91a98
LinuxLinux Kernel5.8 up to, but not including, 6.18.16; 6.19 up to, but not including, 6.19.66.18.16, 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
AdjacentThe attacker must be on the same local network segment.
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:A/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: wifi: iwlwifi: fix 22000 series SMEM parsing If the firmware were to report three LMACs (which doesn't exist in hardware) then using "fwrt->smem_cfg.lmac[2]" is an overrun of the array. Reject such and use IWL_FW_CHECK instead of WARN_ON in this function.

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

The underlying weakness: Improper Validation of Array Index

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How developers prevent this class of flaw

  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
  • Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.

More Improper Validation of Array Index vulnerabilities (CWE-129)

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 Improper Validation of Array Index vulnerabilities

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