Linux: Use After Free
CVE-2026-46166 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 887ece6c23b49d02a6678e7a8d5ad213d75883ce, 7577a4b8a10fab45a6ee2045ea038a5adadbb585, 120149fb3ebcf674832ca3cafd32bedcdb686dde 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 0.2% 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 887ece6c23b49d02a6678e7a8d5ad213d75883ce or 7577a4b8a10fab45a6ee2045ea038a5adadbb585 or 120149fb3ebcf674832ca3cafd32bedcdb686dde or ac8eb3e18f41e2cc8492cc1d358bcb786c850270, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.88 or 6.18.30 or 7.0.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | bca8bc0399ac2efd56e6adbed0307e10125a556c up to, but not including, 887ece6c23b49d02a6678e7a8d5ad213d75883ce; bca8bc0399ac2efd56e6adbed0307e10125a556c up to, but not including, 7577a4b8a10fab45a6ee2045ea038a5adadbb585; bca8bc0399ac2efd56e6adbed0307e10125a556c up to, but not including, 120149fb3ebcf674832ca3cafd32bedcdb686dde; bca8bc0399ac2efd56e6adbed0307e10125a556c up to, but not including, ac8eb3e18f41e2cc8492cc1d358bcb786c850270; 6.12 | 887ece6c23b49d02a6678e7a8d5ad213d75883ce, 7577a4b8a10fab45a6ee2045ea038a5adadbb585, 120149fb3ebcf674832ca3cafd32bedcdb686dde, ac8eb3e18f41e2cc8492cc1d358bcb786c850270 |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Linux | Linux Kernel | 6.12 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.7; 7.1 | 6.12.88, 6.18.30, 7.0.7 |
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
- AdjacentThe attacker must be on the same local network segment.
- 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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA |
| CVSS 3.1 | 7.0 | High | CNA |
Official description
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: use safe list iteration in radar detect work The call to ieee80211_dfs_cac_cancel can cause the iterated chanctx to be freed and removed from the list. Guard against this to avoid a slab-use-after-free 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.
- 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
Other references
- access.redhat.com/errata/RHSA-2026:27288
- access.redhat.com/errata/RHSA-2026:27708
- access.redhat.com/errata/RHSA-2026:27789
- access.redhat.com/errata/RHSA-2026:33215
- access.redhat.com/security/cve/CVE-2026-46166
- bugzilla.redhat.com/show_bug.cgi?id=2482645
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46166.json
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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