SB20260727311 - Use-after-free in Linux kernel fuse

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-64259)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a use-after-free.

The vulnerability exists due to a use-after-free in fuse_uring_commit_fetch() and fuse_uring_send_in_task() when processing commit sqes that reference requests not yet sent to the fuse server. A local user can send crafted commit sqes with request unique or commit-id values for requests that are not yet completed to cause a use-after-free.

The issue is caused by a race condition where a request becomes findable before preparation and memcpy operations are completed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1efd3d474fc0ba74dfd984249bca78807d739812
• https://git.kernel.org/stable/c/a635f427d57e2012102ae4886b48d8955c59fb86
• https://git.kernel.org/stable/c/e1711479e9068ea31b31353a702a51e639c3d059