CVE-2026-33150 | Use After Free in libfuse

libfuse is the reference implementation of the Linux FUSE. From version 3.18.0 to before version 3.18.2, a use-after-free vulnerability in the io_uring subsystem of libfuse allows a local attacker to crash FUSE filesystem processes and potentially execute arbitrary code. When io_uring thread creation fails due to resource exhaustion (e.g., cgroup pids.max), fuse_uring_start() frees the ring pool structure but stores the dangling pointer in the session state, leading to a use-after-free when the session shuts down. The trigger is reliable in containerized environments where cgroup pids.max limits naturally constrain thread creation. This issue has been patched in version 3.18.2.

Published: 2026-03-20 Last update: 2026-03-23 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33150 is rated Low Risk (31.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-33150

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-21 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33150

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2026-33150

OS Trackers for CVE-2026-33150

vendor priority summary link
debian unimportant CVE-2026-33150 unimportant priority: Debian including 1 source packages (fuse3), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-33150
gentoo normal CVE-2026-33150: 1 GLSA(s) (202604-03), 1 atom(s) (sys-fs/fuse); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2026-33150
redhat high — https://access.redhat.com/security/cve/CVE-2026-33150
suse high CVE-2026-33150 severity important: SUSE including 12 source package names (fuse, fuse-devel, …), 161 product×package rows across 27 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (27 product lines)): Known Not Affected 161. https://www.suse.com/security/cve/CVE-2026-33150/
ubuntu medium CVE-2026-33150 medium priority: Ubuntu including 2 source packages (fuse, fuse3), 13 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): not-affected 12, released 1. https://ubuntu.com/security/CVE-2026-33150

Affected software / configurations for CVE-2026-33150

Vendor Product Version Raw CPE
libfuse_project libfuse >= 3.18.0, < 3.18.2 cpe:2.3:a:libfuse_project:libfuse:*:*:*:*:*:*:*:*

References for CVE-2026-33150

cvelogic Threat Intelligence