Linux: Use After Free
CVE-2025-39882 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 b2fbe0f9f80b9cfa1e06ddcf8b863d918394ef1d, b58a26cdd4795c1ce6a80e38e9348885555dacd6, c4901802ed1ce859242e10af06e6a7752cba0497 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 0.16% 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 b2fbe0f9f80b9cfa1e06ddcf8b863d918394ef1d or b58a26cdd4795c1ce6a80e38e9348885555dacd6 or c4901802ed1ce859242e10af06e6a7752cba0497 or 4de37a48b6b58faaded9eb765047cf0d8785ea18, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.107 or 6.12.48 or 6.16.8, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7d98166183d627c0b9daca7672b2191fae0f8a03 up to, but not including, b2fbe0f9f80b9cfa1e06ddcf8b863d918394ef1d; 31ce7c089b50c3d3056c37e0e25e7535e4428ae1 up to, but not including, b58a26cdd4795c1ce6a80e38e9348885555dacd6; fae58d0155a979a8c414bbc12db09dd4b2f910d0 up to, but not including, c4901802ed1ce859242e10af06e6a7752cba0497; 1f403699c40f0806a707a9a6eed3b8904224021a up to, but not including, 4de37a48b6b58faaded9eb765047cf0d8785ea18; 6.6.105 up to, but not including, 6.6.107; 6.12.45 up to, but not including, 6.12.48; 6.16.5 up to, but not including, 6.16.8 | b2fbe0f9f80b9cfa1e06ddcf8b863d918394ef1d, b58a26cdd4795c1ce6a80e38e9348885555dacd6, c4901802ed1ce859242e10af06e6a7752cba0497, 4de37a48b6b58faaded9eb765047cf0d8785ea18, 6.6.107, 6.12.48 |
| Linux | Linux Kernel | 6.6.105 up to, but not including, 6.6.107; 6.12.45 up to, but not including, 6.12.48; 6.16.5 up to, but not including, 6.16.8; 6.17 | 6.6.107, 6.12.48, 6.16.8 |
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 | 8.4 | High | CNA |
| 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: drm/mediatek: fix potential OF node use-after-free The for_each_child_of_node() helper drops the reference it takes to each node as it iterates over children and an explicit of_node_put() is only needed when exiting the loop early. Drop the recently introduced bogus additional reference count decrement at each iteration that could potentially lead to a use-after-free.
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
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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