Linux: Out-of-bounds Write
CVE-2026-64081 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists versions 3c51d99449dc5a01c08a7fce6071d6721f5aac83, 76eb90e2b03de147e12ab68ea8afd8ea0342df0a, 4a1cc9e96b311d2609a6f963a5e35bd4ae730d97 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 0.19% 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 3c51d99449dc5a01c08a7fce6071d6721f5aac83 or 76eb90e2b03de147e12ab68ea8afd8ea0342df0a or 4a1cc9e96b311d2609a6f963a5e35bd4ae730d97, whichever matches your release line, or a later version.
- Update Linux Kernel to 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 | 285a5ea0f542db94c3ed11e01a71abb47d15cbf5 up to, but not including, 3c51d99449dc5a01c08a7fce6071d6721f5aac83; 285a5ea0f542db94c3ed11e01a71abb47d15cbf5 up to, but not including, 76eb90e2b03de147e12ab68ea8afd8ea0342df0a; 285a5ea0f542db94c3ed11e01a71abb47d15cbf5 up to, but not including, 4a1cc9e96b311d2609a6f963a5e35bd4ae730d97; 6.15 | 3c51d99449dc5a01c08a7fce6071d6721f5aac83, 76eb90e2b03de147e12ab68ea8afd8ea0342df0a, 4a1cc9e96b311d2609a6f963a5e35bd4ae730d97 |
| Linux | Linux Kernel | 6.15 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.1 | 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
- 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
- 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:L/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: firmware: arm_ffa: Validate framework notification message layout Framework notifications carry an indirect message in the shared RX buffer. Validate the reported offset and size before using them, reject zero-length payloads, and ensure that any non-header payload starts at the UUID field rather than in the middle of the message header. Use the validated offset and size values for both kmemdup() and the UUID parsing path so malformed firmware data cannot drive an out-of-bounds read or an oversized allocation.
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
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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