Linux: Use After Free
CVE-2026-43440 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 59489ce60d7412ed82fb1d8002faa3102dcd4916, 6c92392602b451e3869f15ab685f8f650e942b13, 87c2302813abc55c46485711a678e3c312b00666 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 0.12% 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 59489ce60d7412ed82fb1d8002faa3102dcd4916 or 6c92392602b451e3869f15ab685f8f650e942b13 or 87c2302813abc55c46485711a678e3c312b00666 or 6.18.19, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.19 or 6.19.9, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | fa3c2f8d9152344a478abb847081c1b5f84a94f5 up to, but not including, 59489ce60d7412ed82fb1d8002faa3102dcd4916; a9a7c3203fdc4d4a8d8a7a3b1ed05d2bb4c6e77e up to, but not including, 6c92392602b451e3869f15ab685f8f650e942b13; f975a0955276579e2176a134366ed586071c7c6a up to, but not including, 87c2302813abc55c46485711a678e3c312b00666; 6.18.16 up to, but not including, 6.18.19; 6.19.6 up to, but not including, 6.19.9 | 59489ce60d7412ed82fb1d8002faa3102dcd4916, 6c92392602b451e3869f15ab685f8f650e942b13, 87c2302813abc55c46485711a678e3c312b00666, 6.18.19, 6.19.9 |
| Linux | Linux Kernel | 6.18.16 up to, but not including, 6.18.19; 6.19.6 up to, but not including, 6.19.9; 7.0 | 6.18.19, 6.19.9 |
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: net/mana: Null service_wq on setup error to prevent double destroy In mana_gd_setup() error path, set gc->service_wq to NULL after destroy_workqueue() to match the cleanup in mana_gd_cleanup(). This prevents a use-after-free if the workqueue pointer is checked after a failed setup.
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
Recent Use After Free vulnerabilities
- 7.3 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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