Linux: Use After Free
CVE-2025-37926 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 a4348710a7267705b75692dc1a000920481d1d92, 1067361a1cc6ad9cdf7acfc47f90012b72ad1502, 8fb3b6c85b7e3127161623586b62abcc366caa20 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 0.56% 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 a4348710a7267705b75692dc1a000920481d1d92 or 1067361a1cc6ad9cdf7acfc47f90012b72ad1502 or 8fb3b6c85b7e3127161623586b62abcc366caa20 or 6323fec65fe54b365961fed260dd579191e46121, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.28 or 6.14.6, 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, a4348710a7267705b75692dc1a000920481d1d92; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 1067361a1cc6ad9cdf7acfc47f90012b72ad1502; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 8fb3b6c85b7e3127161623586b62abcc366caa20; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 6323fec65fe54b365961fed260dd579191e46121; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, a1f46c99d9ea411f9bf30025b912d881d36fc709; 5.15 | a4348710a7267705b75692dc1a000920481d1d92, 1067361a1cc6ad9cdf7acfc47f90012b72ad1502, 8fb3b6c85b7e3127161623586b62abcc366caa20, 6323fec65fe54b365961fed260dd579191e46121, a1f46c99d9ea411f9bf30025b912d881d36fc709 |
| Linux | Linux Kernel | 5.15 up to, but not including, 6.12.28; 6.13 up to, but not including, 6.14.6; 6.15 | 6.12.28, 6.14.6 |
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 | 8.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in ksmbd_session_rpc_open A UAF issue can occur due to a race condition between ksmbd_session_rpc_open() and __session_rpc_close(). Add rpc_lock to the session to protect it.
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
- git.kernel.org/stable/c/1067361a1cc6ad9cdf7acfc47f90012b72ad1502
- git.kernel.org/stable/c/6323fec65fe54b365961fed260dd579191e46121
- git.kernel.org/stable/c/8fb3b6c85b7e3127161623586b62abcc366caa20
- git.kernel.org/stable/c/a1f46c99d9ea411f9bf30025b912d881d36fc709
- git.kernel.org/stable/c/a4348710a7267705b75692dc1a000920481d1d92
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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