Linux: Use After Free
CVE-2026-31527 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 492349e5e4a369a8b62781100a3ade470bf1ce6b, 9a6086d2a828dd2ff74cf9abcae456670febd71f, 7c02a9bd7d14a89065fcf672b86d8e1d1a41d3b1 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 0.13% 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 492349e5e4a369a8b62781100a3ade470bf1ce6b or 9a6086d2a828dd2ff74cf9abcae456670febd71f or 7c02a9bd7d14a89065fcf672b86d8e1d1a41d3b1 or edee7ee5a14c3b33f6d54641f5af5c5e9180992d, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.80 or 6.18.21 or 6.19.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 3d713e0e382e6fcfb4bba1501645b66c129ad60b up to, but not including, 492349e5e4a369a8b62781100a3ade470bf1ce6b; 3d713e0e382e6fcfb4bba1501645b66c129ad60b up to, but not including, 9a6086d2a828dd2ff74cf9abcae456670febd71f; 3d713e0e382e6fcfb4bba1501645b66c129ad60b up to, but not including, 7c02a9bd7d14a89065fcf672b86d8e1d1a41d3b1; 3d713e0e382e6fcfb4bba1501645b66c129ad60b up to, but not including, edee7ee5a14c3b33f6d54641f5af5c5e9180992d; 3d713e0e382e6fcfb4bba1501645b66c129ad60b up to, but not including, 2b38efc05bf7a8568ec74bfffea0f5cfa62bc01d; 3.17 | 492349e5e4a369a8b62781100a3ade470bf1ce6b, 9a6086d2a828dd2ff74cf9abcae456670febd71f, 7c02a9bd7d14a89065fcf672b86d8e1d1a41d3b1, edee7ee5a14c3b33f6d54641f5af5c5e9180992d, 2b38efc05bf7a8568ec74bfffea0f5cfa62bc01d |
| Linux | Linux Kernel | 3.17 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 7.0 | 6.12.80, 6.18.21, 6.19.11 |
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: driver core: platform: use generic driver_override infrastructure When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1]
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
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