Linux: Use After Free
CVE-2025-37882 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 16a7a8e6c47fea5c847beb696c8c21a7a44c1915, 39a080a2925c81b0f1da0add44722ef2b78e5454, 906dec15b9b321b546fd31a3c99ffc13724c7af4 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 0.3% 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 16a7a8e6c47fea5c847beb696c8c21a7a44c1915 or 39a080a2925c81b0f1da0add44722ef2b78e5454 or 906dec15b9b321b546fd31a3c99ffc13724c7af4, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.26 or 6.14.5, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 608b973b70f87e9a9bafbfdfa16aab68507aef45 up to, but not including, 16a7a8e6c47fea5c847beb696c8c21a7a44c1915; 608b973b70f87e9a9bafbfdfa16aab68507aef45 up to, but not including, 39a080a2925c81b0f1da0add44722ef2b78e5454; 608b973b70f87e9a9bafbfdfa16aab68507aef45 up to, but not including, 906dec15b9b321b546fd31a3c99ffc13724c7af4; 6.10 | 16a7a8e6c47fea5c847beb696c8c21a7a44c1915, 39a080a2925c81b0f1da0add44722ef2b78e5454, 906dec15b9b321b546fd31a3c99ffc13724c7af4 |
| Linux | Linux Kernel | before 6.12.26; 6.13 up to, but not including, 6.14.5 | 6.12.26, 6.14.5 |
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: usb: xhci: Fix isochronous Ring Underrun/Overrun event handling The TRB pointer of these events points at enqueue at the time of error occurrence on xHCI 1.1+ HCs or it's NULL on older ones. By the time we are handling the event, a new TD may be queued at this ring position. I can trigger this race by rising interrupt moderation to increase IRQ handling delay. Similar delay may occur naturally due to system load. If this ever happens after a Missed Service Error, missed TDs will be skipped and the new TD processed as if it matched the event. It could be given back prematurely, risking data loss or buffer UAF by the xHC. Don't complete TDs on xrun events and don't warn if queued TDs don't match the event's TRB pointer, which can be NULL or a link/no-op TRB. Don't warn if there are no queued TDs at all. Now that it's safe, also handle xrun events if the skip flag is clear. This ensures completion of any TD stuck in 'error mid TD' state right before the xrun event, which could happen if a driver submits a finite number of URBs to a buggy HC and then an error occurs on the last TD.
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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