CyberSecBulletin
CVE-2026-43330NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-43330 is a high-severity out-of-bounds write 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 31022cfde5235c45fa765f0aabeff5f0652852f2, c2fb4984fe09fc176fe4c12d5e3edf626df6511d, aa545df011338df13f0833fc1fabcb15c0521959 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 31022cfde5235c45fa765f0aabeff5f0652852f2 or c2fb4984fe09fc176fe4c12d5e3edf626df6511d or aa545df011338df13f0833fc1fabcb15c0521959 or cebc5ebd958346195b77f42d0cd5141b4e448fae, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.134 or 6.12.81 or 6.18.22 or 6.19.12, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux199354d7fb6eaa2cc5bb650af0bca624baffee35 up to, but not including, 31022cfde5235c45fa765f0aabeff5f0652852f2; 199354d7fb6eaa2cc5bb650af0bca624baffee35 up to, but not including, c2fb4984fe09fc176fe4c12d5e3edf626df6511d; 199354d7fb6eaa2cc5bb650af0bca624baffee35 up to, but not including, aa545df011338df13f0833fc1fabcb15c0521959; 199354d7fb6eaa2cc5bb650af0bca624baffee35 up to, but not including, cebc5ebd958346195b77f42d0cd5141b4e448fae; 199354d7fb6eaa2cc5bb650af0bca624baffee35 up to, but not including, 80688afb9c35b3934ce2d6be9973758915e2e0ef; 6.331022cfde5235c45fa765f0aabeff5f0652852f2, c2fb4984fe09fc176fe4c12d5e3edf626df6511d, aa545df011338df13f0833fc1fabcb15c0521959, cebc5ebd958346195b77f42d0cd5141b4e448fae, 80688afb9c35b3934ce2d6be9973758915e2e0ef
LinuxLinux Kernel6.3 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; 7.06.6.134, 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
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: crypto: caam - fix overflow on long hmac keys When a key longer than block size is supplied, it is copied and then hashed into the real key. The memory allocated for the copy needs to be rounded to DMA cache alignment, as otherwise the hashed key may corrupt neighbouring memory. The copying is performed using kmemdup, however this leads to an overflow: reading more bytes (aligned_len - keylen) from the keylen source buffer. Fix this by replacing kmemdup with kmalloc, followed by memcpy.

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

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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