Linux: Use After Free
CVE-2025-22041 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 remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions f0eb3f575138b816da74697bd506682574742fcd, a8a8ae303a8395cbac270b5b404d85df6ec788f8, ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9b 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 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to f0eb3f575138b816da74697bd506682574742fcd or a8a8ae303a8395cbac270b5b404d85df6ec788f8 or ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9b or 8ed0e9d2f410f63525afb8351181eea36c80bcf1, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.134 or 6.6.87 or 6.12.13 or 6.13.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, f0eb3f575138b816da74697bd506682574742fcd; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, a8a8ae303a8395cbac270b5b404d85df6ec788f8; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9b; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 8ed0e9d2f410f63525afb8351181eea36c80bcf1; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 33cc29e221df7a3085ae413e8c26c4e81a151153; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 15a9605f8d69dc85005b1a00c31a050b8625e1aa; 5.15 | f0eb3f575138b816da74697bd506682574742fcd, a8a8ae303a8395cbac270b5b404d85df6ec788f8, ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9b, 8ed0e9d2f410f63525afb8351181eea36c80bcf1, 33cc29e221df7a3085ae413e8c26c4e81a151153, 15a9605f8d69dc85005b1a00c31a050b8625e1aa |
| Linux | Linux Kernel | before 6.1.134; 6.2 up to, but not including, 6.6.87; 6.7 up to, but not including, 6.12.13; 6.13 up to, but not including, 6.13.11; 6.14 up to, but not including, 6.14.2 | 6.1.134, 6.6.87, 6.12.13, 6.13.11, 6.14.2 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- 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:N/AC:L/PR:L/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 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in ksmbd_sessions_deregister() In multichannel mode, UAF issue can occur in session_deregister when the second channel sets up a session through the connection of the first channel. session that is freed through the global session table can be accessed again through ->sessions of connection.
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/15a9605f8d69dc85005b1a00c31a050b8625e1aa
- git.kernel.org/stable/c/33cc29e221df7a3085ae413e8c26c4e81a151153
- git.kernel.org/stable/c/8ed0e9d2f410f63525afb8351181eea36c80bcf1
- git.kernel.org/stable/c/a8a8ae303a8395cbac270b5b404d85df6ec788f8
- git.kernel.org/stable/c/ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9b
- git.kernel.org/stable/c/f0eb3f575138b816da74697bd506682574742fcd
Other references
Recent Use After Free vulnerabilities
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
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