Linux: Use After Free
CVE-2026-64261 is a high-severity use after free 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 23a356e0bd96c8d5fb3ddff069f692bf10cab5c1, 95d7f50aff2a5f71557263ff25b97b2951f32bf8, d351da75066955144515cb2f9aa959f24a04287a 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 0.17% 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 23a356e0bd96c8d5fb3ddff069f692bf10cab5c1 or 95d7f50aff2a5f71557263ff25b97b2951f32bf8 or d351da75066955144515cb2f9aa959f24a04287a, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.39 or 7.1.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 4a9bfb9b6850fec0685447aed280533cf980de70 up to, but not including, 23a356e0bd96c8d5fb3ddff069f692bf10cab5c1; 4a9bfb9b6850fec0685447aed280533cf980de70 up to, but not including, 95d7f50aff2a5f71557263ff25b97b2951f32bf8; 4a9bfb9b6850fec0685447aed280533cf980de70 up to, but not including, d351da75066955144515cb2f9aa959f24a04287a; 6.14 | 23a356e0bd96c8d5fb3ddff069f692bf10cab5c1, 95d7f50aff2a5f71557263ff25b97b2951f32bf8, d351da75066955144515cb2f9aa959f24a04287a |
| Linux | Linux Kernel | 6.14 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4 | 6.18.39, 7.1.4 |
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: fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues fuse_uring_async_stop_queues() might run when the last reference on ring->queue_refs was already dropped. In order to avoid an early destruction a reference on struct fuse_conn is now taken before starting fuse_uring_async_stop_queues() and that reference is only released when that delayed work queue terminates.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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