CyberSecBulletin
CVE-2026-43125NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-43125 is a critical-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 0270664871616eb3a5c864b9aa17be76fd35b920, c98d071a1ca903b705316225e47006aaa20e989c, 2deafd015ea9a0e75ee5764e20eb1e16bd73efd8 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 0.54% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 0270664871616eb3a5c864b9aa17be76fd35b920 or c98d071a1ca903b705316225e47006aaa20e989c or 2deafd015ea9a0e75ee5764e20eb1e16bd73efd8 or 67288113c5e6cf9e659b4065c0ed6f16100e0c71, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.12.75 or 6.18.16 or 6.19.6, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, 0270664871616eb3a5c864b9aa17be76fd35b920; 7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, c98d071a1ca903b705316225e47006aaa20e989c; 7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, 2deafd015ea9a0e75ee5764e20eb1e16bd73efd8; 7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, 67288113c5e6cf9e659b4065c0ed6f16100e0c71; 7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, 082083c9fbd99422a0370fe2102144a231c9f5d6; 7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, 5f053a2e7209d326cbbc07738fa6d6893d307438; 7210cb7a72a22303cdb225bd1aea28697a17bbae up to, but not including, 080e5563f878c64e697b89e7439d730d0daad882; 3.40270664871616eb3a5c864b9aa17be76fd35b920, c98d071a1ca903b705316225e47006aaa20e989c, 2deafd015ea9a0e75ee5764e20eb1e16bd73efd8, 67288113c5e6cf9e659b4065c0ed6f16100e0c71, 082083c9fbd99422a0370fe2102144a231c9f5d6, 5f053a2e7209d326cbbc07738fa6d6893d307438
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update ServiceNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP SolutionsNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9.6 Extended Update SupportNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
LinuxLinux Kernel3.4 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, 6.19.66.12.75, 6.18.16, 6.19.6

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalCNA
CVSS 3.17.0HighCNA

Official description

In the Linux kernel, the following vulnerability has been resolved: dlm: validate length in dlm_search_rsb_tree The len parameter in dlm_dump_rsb_name() is not validated and comes from network messages. When it exceeds DLM_RESNAME_MAXLEN, it can cause out-of-bounds write in dlm_search_rsb_tree(). Add length validation to prevent potential buffer overflow.

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: yes, 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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