LibfuseApplication · Libfuse Project

CVE-2026-33150

HIGH · 7.8 CVSS v3.1 Published 2026-03-20
Fix available
A fix is available. Upgrade to 3.18.2 or later.
See remediation →
80/100
Remediation priority · High
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-416

Memory is used after it has been freed, so its contents — now potentially attacker-controlled — drive the program's behaviour. With careful heap grooming this becomes code execution. The fix requires disciplined ownership of memory and often a targeted rework of the object lifecycle.

General guidance for the use after free class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LibfuseApplication
Affected:>= 3.18.0, < 3.18.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.18.2 or later
Fixed in 3.18.2
Vendor patch github.com →
Recommended fix High confidence

libfuse version 3.18.2

  1. Check current libfuse version installed (e.g., dpkg -l | grep libfuse, rpm -qa | grep fuse, or fusermount --version)
  2. Upgrade libfuse to version 3.18.2 or later via package manager or source compilation
  3. For Debian/Ubuntu: apt-get update && apt-get install libfuse3.18.2 or later
  4. For RHEL/CentOS/Fedora: dnf update fuse3 or yum update fuse3
  5. For source compilation: download libfuse 3.18.2 from https://github.com/libfuse/libfuse/releases, extract, run ./configure && make && make install
  6. Restart any FUSE filesystem daemons to ensure they load the updated library
  7. Verify the new version is loaded: ldconfig -p | grep fuse and check the library path points to the updated version

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,200. Get the upgrade done

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Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33150 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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