Linux: Use After Free
CVE-2026-45989 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 0ba03e06f037df704d9b032e36d417633e2326bc, d68347b07b9801791c9eaab8f772770b52b8cd5c, 5b6122a67a295f8a08b7c18d908a1bd974dfaec8 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 0ba03e06f037df704d9b032e36d417633e2326bc or d68347b07b9801791c9eaab8f772770b52b8cd5c or 5b6122a67a295f8a08b7c18d908a1bd974dfaec8 or 6b2023286d2c6ed3bf964fb92e34c9c14d42eb69, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.140 or 6.12.86 or 6.18.27 or 7.0.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 26409dd045892904b059dc411403e9c8ce7543ca up to, but not including, 0ba03e06f037df704d9b032e36d417633e2326bc; 26409dd045892904b059dc411403e9c8ce7543ca up to, but not including, d68347b07b9801791c9eaab8f772770b52b8cd5c; 26409dd045892904b059dc411403e9c8ce7543ca up to, but not including, 5b6122a67a295f8a08b7c18d908a1bd974dfaec8; 26409dd045892904b059dc411403e9c8ce7543ca up to, but not including, 6b2023286d2c6ed3bf964fb92e34c9c14d42eb69; 26409dd045892904b059dc411403e9c8ce7543ca up to, but not including, 07fd339b2c253205794bea5d9b4b7548a4546c56; 6.6 | 0ba03e06f037df704d9b032e36d417633e2326bc, d68347b07b9801791c9eaab8f772770b52b8cd5c, 5b6122a67a295f8a08b7c18d908a1bd974dfaec8, 6b2023286d2c6ed3bf964fb92e34c9c14d42eb69, 07fd339b2c253205794bea5d9b4b7548a4546c56 |
| Linux | Linux Kernel | 6.6 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.86; 6.13 up to, but not including, 6.18.27; 6.19 up to, but not including, 7.0.4 | 6.6.140, 6.12.86, 6.18.27, 7.0.4 |
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: of: unittest: fix use-after-free in testdrv_probe() The function testdrv_probe() retrieves the device_node from the PCI device, applies an overlay, and then immediately calls of_node_put(dn). This releases the reference held by the PCI core, potentially freeing the node if the reference count drops to zero. Later, the same freed pointer 'dn' is passed to of_platform_default_populate(), leading to a use-after-free. The reference to pdev->dev.of_node is owned by the device model and should not be released by the driver. Remove the erroneous of_node_put() to prevent premature freeing.
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/07fd339b2c253205794bea5d9b4b7548a4546c56
- git.kernel.org/stable/c/0ba03e06f037df704d9b032e36d417633e2326bc
- git.kernel.org/stable/c/5b6122a67a295f8a08b7c18d908a1bd974dfaec8
- git.kernel.org/stable/c/6b2023286d2c6ed3bf964fb92e34c9c14d42eb69
- git.kernel.org/stable/c/d68347b07b9801791c9eaab8f772770b52b8cd5c
Recent Use After Free vulnerabilities
- 8.1 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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