CVE Catalog

CVE-2026-64259

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel fuse-uring subsystem, a use-after-free vulnerability exists. A malicious user can send commit SQEs for requests not yet sent to the FUSE server, potentially leading to use-after-free during memcpy operations.

Risk Assessment

An attacker could exploit this vulnerability to execute code in kernel context or cause a system crash.

Recommendation

Apply the Linux kernel patch that moves the fuse_uring_add_to_pq() call after copy operations and before completing the io_uring request.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS