Linux: Double Free
CVE-2025-37817 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 d70184958b0ea8c0fd52e2b456654b503e769fc8, 4ffe8c9fb561e4427dd1a3056cd5b3685b74f78d, 59f993cd36b6e28a394ba3d977e8ffe5c9884e3b 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 0.21% 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 d70184958b0ea8c0fd52e2b456654b503e769fc8 or 4ffe8c9fb561e4427dd1a3056cd5b3685b74f78d or 59f993cd36b6e28a394ba3d977e8ffe5c9884e3b or c5b8a549ef1fcc6066b037a3962c79d60465ba0b, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.293 or 5.10.237 or 5.15.181 or 6.1.136, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, d70184958b0ea8c0fd52e2b456654b503e769fc8; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, 4ffe8c9fb561e4427dd1a3056cd5b3685b74f78d; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, 59f993cd36b6e28a394ba3d977e8ffe5c9884e3b; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, c5b8a549ef1fcc6066b037a3962c79d60465ba0b; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, 96838eb1836fd372e42be5db84f0b333b65146a6; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, df1a5d5c6134224f9298e5189230f9d29ae50cac; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, bcc7d58ee5173e34306026bd01e1fbf75e169d37; 3764e82e5150d87b205c10cd78a9c9ab86fbfa51 up to, but not including, 7c7f1bfdb2249f854a736d9b79778c7e5a29a150; and 1 more ranges | d70184958b0ea8c0fd52e2b456654b503e769fc8, 4ffe8c9fb561e4427dd1a3056cd5b3685b74f78d, 59f993cd36b6e28a394ba3d977e8ffe5c9884e3b, c5b8a549ef1fcc6066b037a3962c79d60465ba0b, 96838eb1836fd372e42be5db84f0b333b65146a6, df1a5d5c6134224f9298e5189230f9d29ae50cac |
| Linux | Linux Kernel | 3.15 up to, but not including, 5.4.293; 5.5 up to, but not including, 5.10.237; 5.11 up to, but not including, 5.15.181; 5.16 up to, but not including, 6.1.136; 6.2 up to, but not including, 6.6.89; 6.7 up to, but not including, 6.12.26; 6.13 up to, but not including, 6.14.5; 6.15 | 5.4.293, 5.10.237, 5.15.181, 6.1.136, 6.6.89, 6.12.26 |
| 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.
Official description
In the Linux kernel, the following vulnerability has been resolved: mcb: fix a double free bug in chameleon_parse_gdd() In chameleon_parse_gdd(), if mcb_device_register() fails, 'mdev' would be released in mcb_device_register() via put_device(). Thus, goto 'err' label and free 'mdev' again causes a double free. Just return if mcb_device_register() fails.
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/4ffe8c9fb561e4427dd1a3056cd5b3685b74f78d
- git.kernel.org/stable/c/59f993cd36b6e28a394ba3d977e8ffe5c9884e3b
- git.kernel.org/stable/c/7c7f1bfdb2249f854a736d9b79778c7e5a29a150
- git.kernel.org/stable/c/96838eb1836fd372e42be5db84f0b333b65146a6
- git.kernel.org/stable/c/bcc7d58ee5173e34306026bd01e1fbf75e169d37
- git.kernel.org/stable/c/c5b8a549ef1fcc6066b037a3962c79d60465ba0b
- git.kernel.org/stable/c/d70184958b0ea8c0fd52e2b456654b503e769fc8
- git.kernel.org/stable/c/df1a5d5c6134224f9298e5189230f9d29ae50cac
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/05/msg00030.htmlMailing List, Third Party Advisory
- lists.debian.org/debian-lts-announce/2025/05/msg00045.htmlMailing List, Third Party Advisory
Recent Double 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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