Vulnerability-Lookup

UBUNTU-CVE-2026-33179 (CVE-2026-33179)

Vulnerability from osv_ubuntu – Published: 2026-03-20 21:17 – Updated: 2026-05-20 15:27 – Source website

Withdrawn 2026-07-28

Details

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.

Severity

5.5 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-33179	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-33179	REPORT
	https://github.com/libfuse/libfuse/releases/tag/f…	REPORT
	https://github.com/libfuse/libfuse/security/advis…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "fuse",
            "binary_version": "3.18.2-1"
          },
          {
            "binary_name": "fuse3",
            "binary_version": "3.18.2-1"
          },
          {
            "binary_name": "libfuse3-4",
            "binary_version": "3.18.2-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "fuse3",
        "purl": "pkg:deb/ubuntu/fuse3@3.18.2-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.17.4-1",
        "3.18.1-1",
        "3.18.2-1"
      ]
    }
  ],
  "aliases": [],
  "details": "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.",
  "id": "UBUNTU-CVE-2026-33179",
  "modified": "2026-05-20T15:27:21Z",
  "published": "2026-03-20T21:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-33179"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-33179"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/libfuse/libfuse/security/advisories/GHSA-x669-v3mq-r358"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-33179"
  ],
  "withdrawn": "2026-07-28T18:33:22Z"
}

CVE-2026-33179 (GCVE-0-2026-33179)

Vulnerability from cvelistv5 – Published: 2026-03-20 20:20 – Updated: 2026-03-25 13:55

Title

libfuse: NULL Pointer Dereference and Memory Leak in io_uring Queue Initialization

Summary

Severity

5.5 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-25 13:55 UTC

CWE

CWE-476 - NULL Pointer Dereference

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/libfuse/libfuse/security/advis…	x_refsource_CONFIRM
https://github.com/libfuse/libfuse/commit/7beb86c…	x_refsource_MISC
https://github.com/libfuse/libfuse/releases/tag/f…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
libfuse	libfuse	Affected: >= 3.18.0, < 3.18.2

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-33179",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-25T13:55:38.887586Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-25T13:55:45.971Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "libfuse",
          "vendor": "libfuse",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.18.0, \u003c 3.18.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476: NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-20T20:20:09.171Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/libfuse/libfuse/security/advisories/GHSA-x669-v3mq-r358",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/libfuse/libfuse/security/advisories/GHSA-x669-v3mq-r358"
        },
        {
          "name": "https://github.com/libfuse/libfuse/commit/7beb86c09b6ec5aab14dc25256ed8a5ad18554d7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libfuse/libfuse/commit/7beb86c09b6ec5aab14dc25256ed8a5ad18554d7"
        },
        {
          "name": "https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2"
        }
      ],
      "source": {
        "advisory": "GHSA-x669-v3mq-r358",
        "discovery": "UNKNOWN"
      },
      "title": "libfuse: NULL Pointer Dereference and Memory Leak in io_uring Queue Initialization"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-33179",
    "datePublished": "2026-03-20T20:20:09.171Z",
    "dateReserved": "2026-03-17T22:16:36.720Z",
    "dateUpdated": "2026-03-25T13:55:45.971Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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UBUNTU-CVE-2026-33179 (CVE-2026-33179)

CVE-2026-33179 (GCVE-0-2026-33179)

Tags

Sightings

Nomenclature

Related by attack behaviour