Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: fuse-uring: make a fuse_req on SQE commit only findable after memcpy Bad userspace might try to trick us and send commit SQEs request unique / commit-id of requests that are not even send to fuse-server (io_uring_cmd_done() not called) yet. fuse_uring_commit_fetch() ends the fuse request when the ring entry has a wrong state, but that could have caused a use-after-free with the memcpy operations in fuse_uring_send_in_task(). In order to avoid such races the call of fuse_uring_add_to_pq() is moved after the copy operations and just before completing the io-uring request - malicious userspace cannot find the request anymore until all prepration work in fuse-client/kernel is completed. This also moves fuse_uring_add_to_pq() a bit up in the code to avoid a forward declaration. Also not with a preparation commit, to make it easier to back port to older kernels.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.14, < 6.18.39 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/1efd3d474fc0ba74dfd984249bca78807d739812Patch
- https://git.kernel.org/stable/c/a635f427d57e2012102ae4886b48d8955c59fb86Patch
- https://git.kernel.org/stable/c/e1711479e9068ea31b31353a702a51e639c3d059Patch
FAQ
What is CVE-2026-64259?
CVE-2026-64259 is a vulnerability with a CVSS score of 7.8 (HIGH). In the Linux kernel, the following vulnerability has been resolved: fuse-uring: make a fuse_req on SQE commit only findable after memcpy Bad userspace might try to trick us and send commit SQEs requ...
How severe is CVE-2026-64259?
CVE-2026-64259 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-64259?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.