Linux: Out-of-bounds Read
CVE-2025-21985 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 36793d90d76f667d26c6dd025571481ee0c96abc, 9aedc776b11038f04f4641241bb7e877781e4aa4, 8adbb2a98b00926315fd513b5fe2596b5716b82d 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 0.2% 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 36793d90d76f667d26c6dd025571481ee0c96abc or 9aedc776b11038f04f4641241bb7e877781e4aa4 or 8adbb2a98b00926315fd513b5fe2596b5716b82d, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.20 or 6.13.8, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c up to, but not including, 36793d90d76f667d26c6dd025571481ee0c96abc; 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c up to, but not including, 9aedc776b11038f04f4641241bb7e877781e4aa4; 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c up to, but not including, 8adbb2a98b00926315fd513b5fe2596b5716b82d; 4.15 | 36793d90d76f667d26c6dd025571481ee0c96abc, 9aedc776b11038f04f4641241bb7e877781e4aa4, 8adbb2a98b00926315fd513b5fe2596b5716b82d |
| Linux | Linux Kernel | 4.15 up to, but not including, 6.12.20; 6.13 up to, but not including, 6.13.8; 6.14 | 6.12.20, 6.13.8 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix out-of-bound accesses [WHAT & HOW] hpo_stream_to_link_encoder_mapping has size MAX_HPO_DP2_ENCODERS(=4), but location can have size up to 6. As a result, it is necessary to check location against MAX_HPO_DP2_ENCODERS. Similiarly, disp_cfg_stream_location can be used as an array index which should be 0..5, so the ASSERT's conditions should be less without equal.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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