Security readout for executives and security teams
Plain-English summary
CVE-2026-33150 affects libfuse 3.18.0 and 3.18.1. A local attacker can cause FUSE filesystem processes to crash and may be able to execute code. The issue is most concerning where containers or cgroup limits make thread creation failures more likely. libfuse 3.18.2 contains the patch.
Executive priority
Treat this as high priority where FUSE is used in containerized Linux environments. It is local, not remote, but the impact includes service crashes and possible code execution. Patch affected libfuse versions promptly through normal Linux package channels.
Technical view
The vulnerability is a use-after-free in libfuse's io_uring subsystem. If io_uring thread creation fails, fuse_uring_start() frees the ring pool but leaves a dangling pointer in session state. Shutdown later reuses that pointer, causing a crash and potential arbitrary code execution.
Likely exposure
Exposure is limited to systems using libfuse versions 3.18.0 through before 3.18.2. Risk is higher for workloads running FUSE filesystems inside containers or cgroup-constrained environments, especially where pids.max can restrict thread creation.
Exploitation context
The source bundle describes local, low-privilege exploitation with no user interaction. It states the trigger is reliable in containerized environments with constrained thread creation. KEV is false, and the provided sources do not claim active exploitation in the wild.
Researcher notes
Evidence supports a narrow version range and a specific io_uring cleanup bug. The patch is linked upstream. The bundle does not provide proof of active exploitation, affected downstream package names, or a universal mitigation beyond upgrading and following vendor guidance.
Mitigation direction
- Upgrade libfuse to version 3.18.2 or later.
- Check vendor advisories for distribution-specific fixed packages.
- Prioritize container hosts and workloads using FUSE filesystems.
- Review appliances or images that bundle libfuse independently.
- Track Red Hat and upstream libfuse guidance for package status.
Validation and detection
- Inventory libfuse versions across hosts, containers, and base images.
- Flag libfuse 3.18.0 and 3.18.1 as affected.
- Identify FUSE filesystem processes using libfuse in production.
- Check containerized FUSE workloads for cgroup pid constraints.
- Confirm patched package versions after remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-825: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-33150 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9GitHub_MCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-03-20T21:01:20.625Z: Reported to Red Hat.
- 2026-03-20T20:20:29.963Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/libfuse/libfuse/security/advisories/GHSA-qxv7-xrc2-qmfxCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/libfuse/libfuse/commit/49fcd891a58f622c098e2ca67d66086f7b213836CVE reference, GitHub_M · x_refsource_MISC
- https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2CVE reference, GitHub_M · x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-33150CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2449771CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33150.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Expired Pointer Dereference
Expired Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.