CVE-2026-33179 | libfuse: NULL Pointer Dereference and Memory Leak in io_uring Queue Initialization

libfuse is the reference implementation of the Linux FUSE. From version 3.18.0 to before version 3.18.2, a NULL pointer dereference and memory leak in fuse_uring_init_queue allows a local user to crash the FUSE daemon or cause resource exhaustion. When numa_alloc_local fails during io_uring queue entry setup, the code proceeds with NULL pointers. When fuse_uring_register_queue fails, NUMA allocations are leaked and the function incorrectly returns success. Only the io_uring transport is affected; the traditional /dev/fuse path is not affected. PoC confirmed with AddressSanitizer/LeakSanitizer. This issue has been patched in version 3.18.2.

Published: 2026-03-20 Last update: 2026-03-27 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33179 is rated Low Risk (22.5/100): CVSS Medium 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-2026-33179

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-2026-33179

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-33179

OS Trackers for CVE-2026-33179

vendor priority summary link
debian unimportant CVE-2026-33179 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-2026-33179
gentoo normal CVE-2026-33179: 1 GLSA(s) (202604-03), 1 atom(s) (sys-fs/fuse); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2026-33179
redhat medium — https://access.redhat.com/security/cve/CVE-2026-33179
suse medium CVE-2026-33179 severity moderate: 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-2026-33179/
ubuntu medium CVE-2026-33179 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-2026-33179

Affected software / configurations for CVE-2026-33179

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

References for CVE-2026-33179

cvelogic Threat Intelligence