CyberSecBulletin
CVE-2026-46234NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-46234 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 f6ec135941d2c1c2dbb87b5ce1783f4f6ac6ccca, caf11dfea5233a69298a1c448bbf8d1639c80536, 01ef69785dc3162f588a361ab770b1e312800188 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 f6ec135941d2c1c2dbb87b5ce1783f4f6ac6ccca or caf11dfea5233a69298a1c448bbf8d1639c80536 or 01ef69785dc3162f588a361ab770b1e312800188 or a998a7e250bf976539e05a00ec64a81292afecaa, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.140, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxb9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, f6ec135941d2c1c2dbb87b5ce1783f4f6ac6ccca; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, caf11dfea5233a69298a1c448bbf8d1639c80536; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, 01ef69785dc3162f588a361ab770b1e312800188; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, a998a7e250bf976539e05a00ec64a81292afecaa; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, 310da27932dd0afe7ce7456dfe1f0814c3301f41; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, 2602f7bb5818e92315feeaeb71d8ce4d5c9ab160; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, 0b68881501460c3761f196469e1e503218c5e536; b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97 up to, but not including, d114bfdc9b76bf93b881e195b7ec957c14227bab; and 1 more rangesf6ec135941d2c1c2dbb87b5ce1783f4f6ac6ccca, caf11dfea5233a69298a1c448bbf8d1639c80536, 01ef69785dc3162f588a361ab770b1e312800188, a998a7e250bf976539e05a00ec64a81292afecaa, 310da27932dd0afe7ce7456dfe1f0814c3301f41, 2602f7bb5818e92315feeaeb71d8ce4d5c9ab160
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel5.5 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 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, 7.0.95.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.90, 6.18.32

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: vsock: fix buffer size clamping order In vsock_update_buffer_size(), the buffer size was being clamped to the maximum first, and then to the minimum. If a user sets a minimum buffer size larger than the maximum, the minimum check overrides the maximum check, inverting the constraint. This breaks the intended socket memory boundaries by allowing the vsk->buffer_size to grow beyond the configured vsk->buffer_max_size. Fix this by checking the minimum first, and then the maximum. This ensures the buffer size never exceeds the buffer_max_size.

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

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