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CVE-2026-31748NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-31748 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 2fc25a4c2e055cd42ea39a1b42c89bfef70e0319, 9f39fa07259eb342908e4aa0271dee038a8ce4f8, f3f8ec00cfb8d8e826e30b1138a56355b88e9ba8 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 2fc25a4c2e055cd42ea39a1b42c89bfef70e0319 or 9f39fa07259eb342908e4aa0271dee038a8ce4f8 or f3f8ec00cfb8d8e826e30b1138a56355b88e9ba8 or c16ac4e173a05011437a2d868f70cc415339065a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.168 or 6.6.134, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, 2fc25a4c2e055cd42ea39a1b42c89bfef70e0319; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, 9f39fa07259eb342908e4aa0271dee038a8ce4f8; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, f3f8ec00cfb8d8e826e30b1138a56355b88e9ba8; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, c16ac4e173a05011437a2d868f70cc415339065a; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, 1bf8761eb59e94bf7b8c17b2a1ee48f14378b172; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, a47ae40339c1048f519df33ff8840731720f57cb; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, c8c607a77aab783f2e38cc2e0f24aa6c8f6d200b; 85acac61096f946a78cf0c4b65f7cebe580693b6 up to, but not including, cc797d4821c754c701d9714b58bea947e31dbbe0; and 1 more ranges2fc25a4c2e055cd42ea39a1b42c89bfef70e0319, 9f39fa07259eb342908e4aa0271dee038a8ce4f8, f3f8ec00cfb8d8e826e30b1138a56355b88e9ba8, c16ac4e173a05011437a2d868f70cc415339065a, 1bf8761eb59e94bf7b8c17b2a1ee48f14378b172, a47ae40339c1048f519df33ff8840731720f57cb
LinuxLinux Kernel2.6.29 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.134; 6.7 up to, but not including, 6.12.81; 6.13 up to, but not including, 6.18.22; 6.19 up to, but not including, 6.19.12; 7.05.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22

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: comedi: me_daq: Fix potential overrun of firmware buffer `me2600_xilinx_download()` loads the firmware that was requested by `request_firmware()`. It is possible for it to overrun the source buffer because it blindly trusts the file format. It reads a data stream length from the first 4 bytes into variable `file_length` and reads the data stream contents of length `file_length` from offset 16 onwards. Although it checks that the supplied firmware is at least 16 bytes long, it does not check that it is long enough to contain the data stream. Add a test to ensure that the supplied firmware is long enough to contain the header and the data stream. On failure, log an error and return `-EINVAL`.

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

References

Recent Out-of-bounds Write vulnerabilities

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