CyberSecBulletin
CVE-2026-43206NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-43206 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 3e04bc310d80b46eaf481f1fefcbcb37a187412d, de8d7a25cd2eb5875b1d8d4fbc7fe4b4138b781f, b4034442cb090e4a980bdcc1540948606cbc951b 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 0.14% 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 3e04bc310d80b46eaf481f1fefcbcb37a187412d or de8d7a25cd2eb5875b1d8d4fbc7fe4b4138b781f or b4034442cb090e4a980bdcc1540948606cbc951b or 4857c37c7ba9aa38b9a4c694e8bd8d0091c87940, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.252 or 5.15.202 or 6.1.165 or 6.6.128, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, 3e04bc310d80b46eaf481f1fefcbcb37a187412d; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, de8d7a25cd2eb5875b1d8d4fbc7fe4b4138b781f; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, b4034442cb090e4a980bdcc1540948606cbc951b; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, 4857c37c7ba9aa38b9a4c694e8bd8d0091c87940; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, 75fb57efdd7863fffbc39db23e9cad7aafda26ed; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, bfcd6b53e1f4feb182952f4ff9a137c36ceaf20b; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, 4e72f419e4ed44cb3b60506752d8688c20a60a9b; 0fc8011f89feb8b2c3008583b777d097e1974660 up to, but not including, 8a70a26c9f34baea6c3199a9862ddaff4554a96d; and 1 more ranges3e04bc310d80b46eaf481f1fefcbcb37a187412d, de8d7a25cd2eb5875b1d8d4fbc7fe4b4138b781f, b4034442cb090e4a980bdcc1540948606cbc951b, 4857c37c7ba9aa38b9a4c694e8bd8d0091c87940, 75fb57efdd7863fffbc39db23e9cad7aafda26ed, bfcd6b53e1f4feb182952f4ff9a137c36ceaf20b
LinuxLinux Kernel4.17 up to, but not including, 5.10.252; 5.11 up to, but not including, 5.15.202; 5.16 up to, but not including, 6.1.165; 6.2 up to, but not including, 6.6.128; 6.7 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.16; 6.19 up to, but not including, 6.19.65.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16

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: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() The kfd_event_page_set() function writes KFD_SIGNAL_EVENT_LIMIT * 8 bytes via memset without checking the buffer size parameter. This allows unprivileged userspace to trigger an out-of bounds kernel memory write by passing a small buffer, leading to potential privilege escalation.

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

References

Recent Out-of-bounds Write vulnerabilities

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