Linux: Out-of-bounds Write
CVE-2026-31743 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 2f6e5b9964d0a63a5ba84fca2642876afb70a662, 784ed4abded1ca4b525fa4cade8b02f8c5d2a087, 6c01e7f11f5e5f22285d19510a9643e2506e13c3 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.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 2f6e5b9964d0a63a5ba84fca2642876afb70a662 or 784ed4abded1ca4b525fa4cade8b02f8c5d2a087 or 6c01e7f11f5e5f22285d19510a9643e2506e13c3 or f9b88613ff402aa6fe8fd020573cb95867ae947e, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.81 or 6.18.22 or 6.19.12, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 737c0c8d07b5f671c0a33cec95965fcb2d2ea893 up to, but not including, 2f6e5b9964d0a63a5ba84fca2642876afb70a662; 737c0c8d07b5f671c0a33cec95965fcb2d2ea893 up to, but not including, 784ed4abded1ca4b525fa4cade8b02f8c5d2a087; 737c0c8d07b5f671c0a33cec95965fcb2d2ea893 up to, but not including, 6c01e7f11f5e5f22285d19510a9643e2506e13c3; 737c0c8d07b5f671c0a33cec95965fcb2d2ea893 up to, but not including, f9b88613ff402aa6fe8fd020573cb95867ae947e; 6.9 | 2f6e5b9964d0a63a5ba84fca2642876afb70a662, 784ed4abded1ca4b525fa4cade8b02f8c5d2a087, 6c01e7f11f5e5f22285d19510a9643e2506e13c3, f9b88613ff402aa6fe8fd020573cb95867ae947e |
| Linux | Linux Kernel | 6.9 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; 7.0 | 6.12.81, 6.18.22, 6.19.12 |
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: nvmem: zynqmp_nvmem: Fix buffer size in DMA and memcpy Buffer size used in dma allocation and memcpy is wrong. It can lead to undersized DMA buffer access and possible memory corruption. use correct buffer size in dma_alloc_coherent and memcpy.
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.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Write vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
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