Linux: Out-of-bounds Write
CVE-2026-64515 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 8.3 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 1f573e17bcb7275ddd1c8f47f46ae0faf0e902a4, 55c479aae99b120489a432db9c717484e523dfd6, 722b3f86df80644463d29fe5451e30a617f74500 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 0.24% 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 1f573e17bcb7275ddd1c8f47f46ae0faf0e902a4 or 55c479aae99b120489a432db9c717484e523dfd6 or 722b3f86df80644463d29fe5451e30a617f74500 or a74e893f30db64cdce0fc7a96d3baa417bcd55f5, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.92 or 6.18.34 or 7.0.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 4d70e9c5488dd57ff5fcabe4d4ecf3d9dd4555ff up to, but not including, 1f573e17bcb7275ddd1c8f47f46ae0faf0e902a4; 4d70e9c5488dd57ff5fcabe4d4ecf3d9dd4555ff up to, but not including, 55c479aae99b120489a432db9c717484e523dfd6; 4d70e9c5488dd57ff5fcabe4d4ecf3d9dd4555ff up to, but not including, 722b3f86df80644463d29fe5451e30a617f74500; 4d70e9c5488dd57ff5fcabe4d4ecf3d9dd4555ff up to, but not including, a74e893f30db64cdce0fc7a96d3baa417bcd55f5; 6.9 | 1f573e17bcb7275ddd1c8f47f46ae0faf0e902a4, 55c479aae99b120489a432db9c717484e523dfd6, 722b3f86df80644463d29fe5451e30a617f74500, a74e893f30db64cdce0fc7a96d3baa417bcd55f5 |
| Linux | Linux Kernel | 6.9 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; 7.1 | 6.12.92, 6.18.34, 7.0.11 |
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
- AdjacentThe attacker must be on the same local network segment.
- 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
- LowLimited modification of data is possible.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix MLE defragmentation If either reconf or EPCS multi-link element (MLE) is contained in a non-transmitted profile, the defragmentation routine is called with a pointer to the defragmented copy, but the original elements. This is incorrect for two reasons: - if the original defragmentation was needed, it will not find the correct data - if the original frame is at a higher address, the parsing will potentially overrun the heap data (though given the layout of the buffers, only into the new defragmentation buffer, and then it has to stop and fail once that's filled with copied data. Fix it by tracking the container along with the pointer and in doing so also unify the two almost identical defragmentation routines.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 8.1 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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