SB20260425203 - Gentoo update for FUSE
Published: April 25, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-33150)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to use-after-free in the io_uring subsystem of libfuse when io_uring thread creation fails and the session later shuts down. A local user can trigger resource exhaustion that causes thread creation to fail to execute arbitrary code.
The issue can also crash FUSE filesystem processes using the io_uring transport on session shutdown. The io_uring transport must be explicitly enabled, and the trigger is reliable in containerized environments where cgroup pids.max limits constrain thread creation.
2) NULL pointer dereference (CVE-ID: CVE-2026-33179)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: 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/E:U/U:Clear
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to null pointer dereference in fuse_uring_init_queue when initializing io_uring queue entries after NUMA allocation failure. A local user can trigger allocation failure conditions to cause a denial of service.
Only the io_uring transport is affected; the traditional /dev/fuse path is not affected.
Remediation
Install update from vendor's website.