Linux: Use After Free
CVE-2026-64481 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 b3647e5b7b817272fdef057948c37fcb0704edc7, 3e339c88b8c3044919fd1936a8b23124285d0de6, 8947215c0136c9d905e4a46d824824f8b48a2e5b 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 0.18% 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 b3647e5b7b817272fdef057948c37fcb0704edc7 or 3e339c88b8c3044919fd1936a8b23124285d0de6 or 8947215c0136c9d905e4a46d824824f8b48a2e5b or ce0a903d0591e3e2c790c5b628802b08d1b287cc, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.191 or 6.6.160 or 6.12.97 or 6.18.39, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 47ceabd99a28399f8971f4ca0a37ebc0a21dd2a8 up to, but not including, b3647e5b7b817272fdef057948c37fcb0704edc7; 47ceabd99a28399f8971f4ca0a37ebc0a21dd2a8 up to, but not including, 3e339c88b8c3044919fd1936a8b23124285d0de6; 47ceabd99a28399f8971f4ca0a37ebc0a21dd2a8 up to, but not including, 8947215c0136c9d905e4a46d824824f8b48a2e5b; 47ceabd99a28399f8971f4ca0a37ebc0a21dd2a8 up to, but not including, ce0a903d0591e3e2c790c5b628802b08d1b287cc; 47ceabd99a28399f8971f4ca0a37ebc0a21dd2a8 up to, but not including, d6a40a4d083ef74d00c8f9516cb5ff07ac70720b; 47ceabd99a28399f8971f4ca0a37ebc0a21dd2a8 up to, but not including, b65020d5398f499c09498c9786dba6d67ae57664; 6.0 | b3647e5b7b817272fdef057948c37fcb0704edc7, 3e339c88b8c3044919fd1936a8b23124285d0de6, 8947215c0136c9d905e4a46d824824f8b48a2e5b, ce0a903d0591e3e2c790c5b628802b08d1b287cc, d6a40a4d083ef74d00c8f9516cb5ff07ac70720b, b65020d5398f499c09498c9786dba6d67ae57664 |
| Linux | Linux Kernel | 6.0 up to, but not including, 6.1.191; 6.2 up to, but not including, 6.6.160; 6.7 up to, but not including, 6.12.97; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4 | 6.1.191, 6.6.160, 6.12.97, 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: ALSA: hda/cs35l41: Fix firmware load work teardown cs35l41_hda creates ALSA controls whose private data points at the cs35l41_hda object. The firmware load control can also queue fw_load_work. Those controls are not removed on component unbind, and device remove only cancels fw_load_work through cs35l41_remove_dsp(). That helper is skipped when halo_initialized is false. With firmware_autostart disabled, a firmware load can be requested before the DSP has been initialized. If the component or device is removed before the queued work runs, the worker can run after teardown and dereference driver state that is no longer valid. Track the created controls and remove them on unbind so no new control callback can reach the driver data or queue more work. Then cancel fw_load_work to drain any request that was already queued. Also cancel the work unconditionally during device remove before runtime PM teardown.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/3e339c88b8c3044919fd1936a8b23124285d0de6
- git.kernel.org/stable/c/8947215c0136c9d905e4a46d824824f8b48a2e5b
- git.kernel.org/stable/c/b3647e5b7b817272fdef057948c37fcb0704edc7
- git.kernel.org/stable/c/b65020d5398f499c09498c9786dba6d67ae57664
- git.kernel.org/stable/c/ce0a903d0591e3e2c790c5b628802b08d1b287cc
- git.kernel.org/stable/c/d6a40a4d083ef74d00c8f9516cb5ff07ac70720b
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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