Linux: Use After Free
CVE-2026-46210 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 96889fcdb0988108a19a29b0467717a503651a73, 494ffd1712a588e590e6b1e9f876a8c8b24a9180, 3d9593ad1a58c5acc3e5fa2a48222bb7632e6812 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 0.13% 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 96889fcdb0988108a19a29b0467717a503651a73 or 494ffd1712a588e590e6b1e9f876a8c8b24a9180 or 3d9593ad1a58c5acc3e5fa2a48222bb7632e6812, whichever matches your release line, or a later version.
- Update Linux Kernel to 7.0.9 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 5ad964ad5656668399f00c76707f0d063b64a4b1 up to, but not including, 96889fcdb0988108a19a29b0467717a503651a73; 5ad964ad5656668399f00c76707f0d063b64a4b1 up to, but not including, 494ffd1712a588e590e6b1e9f876a8c8b24a9180; 5ad964ad5656668399f00c76707f0d063b64a4b1 up to, but not including, 3d9593ad1a58c5acc3e5fa2a48222bb7632e6812; 6.18 | 96889fcdb0988108a19a29b0467717a503651a73, 494ffd1712a588e590e6b1e9f876a8c8b24a9180, 3d9593ad1a58c5acc3e5fa2a48222bb7632e6812 |
| Linux | Linux Kernel | 6.18 up to, but not including, 7.0.9; 7.1 | 7.0.9 |
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: media: iris: fix use-after-free of fmt_src during MBPF check During concurrency testing, multiple instances can run in parallel, and each instance uses its own inst->lock while the core->lock protects the list of active instances. The race happens because these locks cover different scopes, inst->lock protects only the internals of a single instance, while the Macro Blocks Per Frame (MBPF) checker walks the core list under core->lock and reads fields like fmt_src->width and fmt_src->height. At the same time, iris_close() may free fmt_src and fmt_dst under inst->lock while the instance is still present in the core list. This allows a situation where the MBPF checker, still iterating through the core list, reaches an instance whose fmt_src was already freed by another thread and ends up dereferencing a dangling pointer, resulting in a use-after-free. This happens because the MBPF checker assumes that any instance in the core list is fully valid, but the freeing of fmt_src and fmt_dst without removing the instance from the core list is not correct. The correct ordering is to defer freeing fmt_src and fmt_dst until after the instance has been removed from the core list and all teardown under the core lock has completed, ensuring that no dangling pointers are ever exposed during MBPF checks.
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
Other references
Recent Use After Free vulnerabilities
- 8.3 High severity
- 8.8 High severity
- 8.3 High severity
- 8.3 High severity
- 8.8 High severity
- 7.5 High severity
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