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CVE-2026-31747NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-31747 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 8ddfe6495c245226a30d8b36e2f4a7aa7712e8d6, 64b24b713e1a3ea6624480594b4f8c2ff86502f2, f72b5567f7c117b46b4058dc6a0c7554f8565561 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 8ddfe6495c245226a30d8b36e2f4a7aa7712e8d6 or 64b24b713e1a3ea6624480594b4f8c2ff86502f2 or f72b5567f7c117b46b4058dc6a0c7554f8565561 or 1603dd471f47762e9d1f52304edb3e49a7e62655, 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
LinuxLinuxac584af599452748187cf6d7865b1607c54ee443 up to, but not including, 8ddfe6495c245226a30d8b36e2f4a7aa7712e8d6; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, 64b24b713e1a3ea6624480594b4f8c2ff86502f2; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, f72b5567f7c117b46b4058dc6a0c7554f8565561; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, 1603dd471f47762e9d1f52304edb3e49a7e62655; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, 99f31aa98ab6e3805c455b65bcd01b3d48bdf1a5; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, eae19cab44204537f79146f15a51811b13227c38; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, de3f923ae7d91480ed3ecea1b1e1fc0dc25b597d; ac584af599452748187cf6d7865b1607c54ee443 up to, but not including, 3fb43a7a5b44713f892c58ead2e5f3a1bc9f4ee7; and 1 more ranges8ddfe6495c245226a30d8b36e2f4a7aa7712e8d6, 64b24b713e1a3ea6624480594b4f8c2ff86502f2, f72b5567f7c117b46b4058dc6a0c7554f8565561, 1603dd471f47762e9d1f52304edb3e49a7e62655, 99f31aa98ab6e3805c455b65bcd01b3d48bdf1a5, eae19cab44204537f79146f15a51811b13227c38
LinuxLinux Kernel3.19 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: me4000: Fix potential overrun of firmware buffer `me4000_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. 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`. Note: The firmware loading was totally broken before commit ac584af59945 ("staging: comedi: me4000: fix firmware downloading"), but that is the most sensible target for this fix.

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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