CyberSecBulletin
CVE-2026-64243NVD status: Modified

Linux: Improper Validation of Array Index

Published Updated By the CyberSecBulletin desk

CVE-2026-64243 is a high-severity improper validation of array index vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 6fb653b62f169f6050fac45b56bf21ad097e19f6, d8cc3e747b002a8b965c529de79c0654675b9a1a, 5fe860af8630cf7c78523cbd68e5a234743585aa 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 0.16% 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 6fb653b62f169f6050fac45b56bf21ad097e19f6 or d8cc3e747b002a8b965c529de79c0654675b9a1a or 5fe860af8630cf7c78523cbd68e5a234743585aa or 2ff3ac6f7664fe5639cad01712ac5e021fa7939c, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.15.210 or 6.1.176 or 6.6.143 or 6.12.93, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, 6fb653b62f169f6050fac45b56bf21ad097e19f6; 342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, d8cc3e747b002a8b965c529de79c0654675b9a1a; 342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, 5fe860af8630cf7c78523cbd68e5a234743585aa; 342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, 2ff3ac6f7664fe5639cad01712ac5e021fa7939c; 342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, 164dcbec9632ca93ae313e6da6e4e05584fa0f02; 342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, 05ef77f02607a3dc5d7f9762cb990f76843315d4; 342fbb7578d1741ff646d7b08e14e8753267b9fa up to, but not including, f63ad68e18d774a5d15cd7e405ead63f6b322679; 5.116fb653b62f169f6050fac45b56bf21ad097e19f6, d8cc3e747b002a8b965c529de79c0654675b9a1a, 5fe860af8630cf7c78523cbd68e5a234743585aa, 2ff3ac6f7664fe5639cad01712ac5e021fa7939c, 164dcbec9632ca93ae313e6da6e4e05584fa0f02, 05ef77f02607a3dc5d7f9762cb990f76843315d4
LinuxLinux Kernel5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.15.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12

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
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
NoneNothing can be modified.
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:N/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: simple-mux: Fix enum control bounds check simple_mux_control_put() rejects values greater than e->items, but enum control values are zero based. For the two-entry mux used by this driver, valid values are 0 and 1, so value 2 must be rejected as well. Accepting e->items can store an invalid mux state, pass it to the GPIO setter, and pass it on to the DAPM mux update path where it is used as an index into the enum text array. Use the same >= e->items check used by the ASoC enum helpers.

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

References

Recent Improper Validation of Array Index vulnerabilities

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