Linux: Use After Free
CVE-2026-64226 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 cf396941901858b0de426cdcd3974eea6a02c98c, 45c7c4e3db8b700307313c035ea08be829a7f21b, 57e19ba3f58a67eb924022a5a60b67fd08e5cbbd 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 cf396941901858b0de426cdcd3974eea6a02c98c or 45c7c4e3db8b700307313c035ea08be829a7f21b or 57e19ba3f58a67eb924022a5a60b67fd08e5cbbd or 9a415cc53711f2238e0f0ca8a6bcc796c003b127, 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 | f0e1a0643a59bf1f922fa209cec86a170b784f3f up to, but not including, cf396941901858b0de426cdcd3974eea6a02c98c; f0e1a0643a59bf1f922fa209cec86a170b784f3f up to, but not including, 45c7c4e3db8b700307313c035ea08be829a7f21b; f0e1a0643a59bf1f922fa209cec86a170b784f3f up to, but not including, 57e19ba3f58a67eb924022a5a60b67fd08e5cbbd; f0e1a0643a59bf1f922fa209cec86a170b784f3f up to, but not including, 9a415cc53711f2238e0f0ca8a6bcc796c003b127; 6.12 | cf396941901858b0de426cdcd3974eea6a02c98c, 45c7c4e3db8b700307313c035ea08be829a7f21b, 57e19ba3f58a67eb924022a5a60b67fd08e5cbbd, 9a415cc53711f2238e0f0ca8a6bcc796c003b127 |
| Linux | Linux Kernel | 6.12 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
- 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: sched_ext: Avoid UAF in scx_root_enable_workfn() init failure path In scx_root_enable_workfn(), put_task_struct(p) is called before scx_error() dereferences p->comm and p->pid. If the iterator's reference is the last drop, the task is freed synchronously and the deref becomes a UAF. Move put_task_struct() past scx_error().
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
- 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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