CyberSecBulletin
CVE-2026-46136NVD status: Undergoing Analysis

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-46136 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 2a79b1a492bcfa725383b6580cd93a6862308c85, e451c325b000b9a0081fd93bc6d103d6943d4b55, 90cc573fd2f46ddbc2c329e7814b5ba3deb7b939 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 2a79b1a492bcfa725383b6580cd93a6862308c85 or e451c325b000b9a0081fd93bc6d103d6943d4b55 or 90cc573fd2f46ddbc2c329e7814b5ba3deb7b939 or 0aa63d33742b805d1a218d18d12b983cce4b2f7b, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.175 or 6.6.140 or 6.12.88 or 6.18.30, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0c9318d49e501a5d50b02bd91a4813bde2353488 up to, but not including, 2a79b1a492bcfa725383b6580cd93a6862308c85; 15173a1697236793e9e900b82fece6f99d41b2a7 up to, but not including, e451c325b000b9a0081fd93bc6d103d6943d4b55; fa6ad88e023ddfa6c5dcdb466d159e89f451e305 up to, but not including, 90cc573fd2f46ddbc2c329e7814b5ba3deb7b939; fa6ad88e023ddfa6c5dcdb466d159e89f451e305 up to, but not including, 0aa63d33742b805d1a218d18d12b983cce4b2f7b; fa6ad88e023ddfa6c5dcdb466d159e89f451e305 up to, but not including, a0111847f0b4f6023f6dd320114697514e024ba3; fa6ad88e023ddfa6c5dcdb466d159e89f451e305 up to, but not including, 5373f8b19e568b5c217832b9bbef165bd2b2df14; 5c8cac512844ad593d31258e215908014381bee2; 6.1.75 up to, but not including, 6.1.175; and 3 more ranges2a79b1a492bcfa725383b6580cd93a6862308c85, e451c325b000b9a0081fd93bc6d103d6943d4b55, 90cc573fd2f46ddbc2c329e7814b5ba3deb7b939, 0aa63d33742b805d1a218d18d12b983cce4b2f7b, a0111847f0b4f6023f6dd320114697514e024ba3, 5373f8b19e568b5c217832b9bbef165bd2b2df14
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel6.1.75 up to, but not including, 6.1.175; 6.6.14 up to, but not including, 6.6.140; 6.7.2 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.76.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7

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 NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921: fix a potential clc buffer length underflow The buf_len is used to limit the iterations for retrieving the country power setting and may underflow under certain conditions due to changes in the power table in CLC. This underflow leads to an almost infinite loop or an invalid power setting resulting in driver initialization failure.

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. 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 Out-of-bounds Write vulnerabilities

Spotted an error? Tell us.