Linux: Use After Free
CVE-2025-21979 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 8930a3e1568cf534f86c8ed2def817c6d0528fc1, 0272d4af7f92997541d8bbf4c51918b93ded6ee2, 75d262ad3c36d52852d764588fcd887f0fcd9138 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 0.22% 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 8930a3e1568cf534f86c8ed2def817c6d0528fc1 or 0272d4af7f92997541d8bbf4c51918b93ded6ee2 or 75d262ad3c36d52852d764588fcd887f0fcd9138 or a5158d67bff06cb6fea31be39aeb319fd908ed8e, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.132 or 6.6.84 or 6.12.20 or 6.13.8, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | ddb1bfbf4ab5c753954d0cd728253b642934a9f2 up to, but not including, 8930a3e1568cf534f86c8ed2def817c6d0528fc1; 3fcc6d7d5f40dad56dee7bde787b7e23edd4b93c up to, but not including, 0272d4af7f92997541d8bbf4c51918b93ded6ee2; a3ee4dc84c4e9d14cb34dad095fd678127aca5b6 up to, but not including, 75d262ad3c36d52852d764588fcd887f0fcd9138; a3ee4dc84c4e9d14cb34dad095fd678127aca5b6 up to, but not including, a5158d67bff06cb6fea31be39aeb319fd908ed8e; a3ee4dc84c4e9d14cb34dad095fd678127aca5b6 up to, but not including, dea22de162058216a90f2706f0d0b36f0ff309fd; a3ee4dc84c4e9d14cb34dad095fd678127aca5b6 up to, but not including, 72d520476a2fab6f3489e8388ab524985d6c4b90; 6.1.57 up to, but not including, 6.1.132; 6.5 | 8930a3e1568cf534f86c8ed2def817c6d0528fc1, 0272d4af7f92997541d8bbf4c51918b93ded6ee2, 75d262ad3c36d52852d764588fcd887f0fcd9138, a5158d67bff06cb6fea31be39aeb319fd908ed8e, dea22de162058216a90f2706f0d0b36f0ff309fd, 72d520476a2fab6f3489e8388ab524985d6c4b90 |
| Linux | Linux Kernel | 6.1.57 up to, but not including, 6.1.132; 6.5 up to, but not including, 6.6.84; 6.7 up to, but not including, 6.12.20; 6.13 up to, but not including, 6.13.8; 6.14 | 6.1.132, 6.6.84, 6.12.20, 6.13.8 |
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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: cancel wiphy_work before freeing wiphy A wiphy_work can be queued from the moment the wiphy is allocated and initialized (i.e. wiphy_new_nm). When a wiphy_work is queued, the rdev::wiphy_work is getting queued. If wiphy_free is called before the rdev::wiphy_work had a chance to run, the wiphy memory will be freed, and then when it eventally gets to run it'll use invalid memory. Fix this by canceling the work before freeing the wiphy.
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/0272d4af7f92997541d8bbf4c51918b93ded6ee2
- git.kernel.org/stable/c/72d520476a2fab6f3489e8388ab524985d6c4b90
- git.kernel.org/stable/c/75d262ad3c36d52852d764588fcd887f0fcd9138
- git.kernel.org/stable/c/8930a3e1568cf534f86c8ed2def817c6d0528fc1
- git.kernel.org/stable/c/a5158d67bff06cb6fea31be39aeb319fd908ed8e
- git.kernel.org/stable/c/dea22de162058216a90f2706f0d0b36f0ff309fd
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html
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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