CyberSecBulletin
CVE-2026-52914NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-52914 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 e4f3f6b818aa6a678bc54a2d4e0bece2303c6a64, 37be61825b15534a16ff9cfc9546de155b6df982, 975563c5de1123dde1ec7946bf5556d20c89d74e 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 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to e4f3f6b818aa6a678bc54a2d4e0bece2303c6a64 or 37be61825b15534a16ff9cfc9546de155b6df982 or 975563c5de1123dde1ec7946bf5556d20c89d74e or f653b040dad1af70fa5cd4fe085e4758925480c9, 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 6.6.142, 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
LinuxLinux610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, e4f3f6b818aa6a678bc54a2d4e0bece2303c6a64; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, 37be61825b15534a16ff9cfc9546de155b6df982; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, 975563c5de1123dde1ec7946bf5556d20c89d74e; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, f653b040dad1af70fa5cd4fe085e4758925480c9; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, e910dbf509125fe51ad68e4fa74dc8ab0a8e787a; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, 3eb8bcb823391bd58997831b3c9c152a4ba8e255; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, fdb2c96efb2baeb3725e9ce3ede8f1e36f5490f0; 610bfc6bc99bc83680d190ebc69359a05fc7f605 up to, but not including, 9cd3f16c320bfdadd4509358122368deb56a5741; and 1 more rangese4f3f6b818aa6a678bc54a2d4e0bece2303c6a64, 37be61825b15534a16ff9cfc9546de155b6df982, 975563c5de1123dde1ec7946bf5556d20c89d74e, f653b040dad1af70fa5cd4fe085e4758925480c9, e910dbf509125fe51ad68e4fa74dc8ab0a8e787a, 3eb8bcb823391bd58997831b3c9c152a4ba8e255
LinuxLinux Kernel3.13 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, 6.6.142; 6.7 up to, but not including, 6.12.92; 6.13 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.15.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix fragment reassembly length accounting batman-adv keeps a running payload length for queued fragments and uses it to validate a fragment chain before reassembly. That accounting currently allows the accumulated fragment length to be truncated during updates. As a result, malformed fragment chains can bypass the intended validation and drive reassembly with inconsistent length state, leading to a local denial of service. Fix the accounting by storing the accumulated length in a length-typed field and rejecting update overflows before the existing validation logic runs. The fix was verified against the original reproducer and against valid fragment reassembly paths.

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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