Linux: Double Free
CVE-2025-38206 is a high-severity double 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 13d8de1b6568dcc31a95534ced16bc0c9a67bc15, 66e84439ec2af776ce749e8540f8fdd257774152, ea27703eb0efbadcd45b9949526160ed90536a72 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 0.19% 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 13d8de1b6568dcc31a95534ced16bc0c9a67bc15 or 66e84439ec2af776ce749e8540f8fdd257774152 or ea27703eb0efbadcd45b9949526160ed90536a72 or ac65f76db9b2ff3fbc9e198c0e9aaf81b111b7d0, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.239 or 5.15.186 or 6.15.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, 13d8de1b6568dcc31a95534ced16bc0c9a67bc15; 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, 66e84439ec2af776ce749e8540f8fdd257774152; 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, ea27703eb0efbadcd45b9949526160ed90536a72; 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, ac65f76db9b2ff3fbc9e198c0e9aaf81b111b7d0; 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, 29abaf93357f4a7d083cf399d4306999e20db31d; 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, d3cef0e7a5c1aa6217c51faa9ce8ecac35d6e1fd; 1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003 up to, but not including, 1f3d9724e16d62c7d42c67d6613b8512f2887c22; 5.7 | 13d8de1b6568dcc31a95534ced16bc0c9a67bc15, 66e84439ec2af776ce749e8540f8fdd257774152, ea27703eb0efbadcd45b9949526160ed90536a72, ac65f76db9b2ff3fbc9e198c0e9aaf81b111b7d0, 29abaf93357f4a7d083cf399d4306999e20db31d, d3cef0e7a5c1aa6217c51faa9ce8ecac35d6e1fd |
| Linux | Linux Kernel | 5.7 up to, but not including, 5.10.239; 5.11 up to, but not including, 5.15.186; 5.16 up to, but not including, 6.15.4 | 5.10.239, 5.15.186, 6.15.4 |
| Debian | Debian Linux | 11.0 | Not stated |
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 | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: exfat: fix double free in delayed_free The double free could happen in the following path. exfat_create_upcase_table() exfat_create_upcase_table() : return error exfat_free_upcase_table() : free ->vol_utbl exfat_load_default_upcase_table : return error exfat_kill_sb() delayed_free() exfat_free_upcase_table() <--------- double free This patch set ->vol_util as NULL after freeing it.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
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
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlMailing List, Third Party Advisory
Other references
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
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