CVE-2026-84894 (GCVE-0-2026-84894)

Vulnerability from cvelistv5 – Published: 2026-09-28 18:40 – Updated: 2026-09-30 15:05
VLAI
Summary
In moxygen before commit 004123dd24c3, MoQSession::dataStreamReadLoop keeps using a stream read handle after reading a FIN, which invalidates the handle under proxygen's WebTransport API. A remote peer can trigger the stale use by opening a data stream that names an unknown track alias and carries the FIN in the same write.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-30 15:05 UTC
CWE
  • Use After Free (CWE-416)
  • CWE-416 - Use After Free
Assigner
References
Impacted products
Vendor Product Version CPE status
Meta Platforms, Inc moxygen Affected: b24f8e65cb83ebe5f3880cc4e3a4c8f64e1882f9 , < 004123dd24c30dad6b649163575145f240dabc94 (git)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-84894",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-30T15:05:21.880556Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-416",
                "description": "CWE-416 Use After Free",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-30T15:05:50.817Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "moxygen",
          "vendor": "Meta Platforms, Inc",
          "versions": [
            {
              "lessThan": "004123dd24c30dad6b649163575145f240dabc94",
              "status": "affected",
              "version": "b24f8e65cb83ebe5f3880cc4e3a4c8f64e1882f9",
              "versionType": "git"
            }
          ]
        }
      ],
      "dateAssigned": "2026-09-02T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "In moxygen before commit 004123dd24c3, MoQSession::dataStreamReadLoop keeps using a stream read handle after reading a FIN, which invalidates the handle under proxygen\u0027s WebTransport API. A remote peer can trigger the stale use by opening a data stream that names an unknown track alias and carries the FIN in the same write."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Use After Free (CWE-416)",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-28T18:40:55.707Z",
        "orgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827",
        "shortName": "Meta"
      },
      "references": [
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://www.facebook.com/security/advisories/cve-2026-84894"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/facebookexperimental/moxygen/commit/004123dd24c30dad6b649163575145f240dabc94"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827",
    "assignerShortName": "Meta",
    "cveId": "CVE-2026-84894",
    "datePublished": "2026-09-28T18:40:55.707Z",
    "dateReserved": "2026-09-02T14:52:36.354Z",
    "dateUpdated": "2026-09-30T15:05:50.817Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-84894",
      "date": "2026-09-30",
      "epss": "0.00145",
      "percentile": "0.03149"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "moxygen",
                "vendor": "Meta Platforms, Inc",
                "versions": [
                  {
                    "lessThan": "004123dd24c30dad6b649163575145f240dabc94",
                    "status": "affected",
                    "version": "b24f8e65cb83ebe5f3880cc4e3a4c8f64e1882f9",
                    "versionType": "git"
                  }
                ]
              }
            ],
            "source": "cve-assign@fb.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In moxygen before commit 004123dd24c3, MoQSession::dataStreamReadLoop keeps using a stream read handle after reading a FIN, which invalidates the handle under proxygen\u0027s WebTransport API. A remote peer can trigger the stale use by opening a data stream that names an unknown track alias and carries the FIN in the same write."
          }
        ],
        "id": "CVE-2026-84894",
        "lastModified": "2026-09-30T19:57:08.043",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-84894",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-30T15:05:21.880556Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-09-28T19:16:50.213",
        "references": [
          {
            "source": "cve-assign@fb.com",
            "url": "https://github.com/facebookexperimental/moxygen/commit/004123dd24c30dad6b649163575145f240dabc94"
          },
          {
            "source": "cve-assign@fb.com",
            "url": "https://www.facebook.com/security/advisories/cve-2026-84894"
          }
        ],
        "sourceIdentifier": "cve-assign@fb.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-416"
              }
            ],
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "NONE",
                  "baseScore": 7.5,
                  "baseSeverity": "HIGH",
                  "confidentialityImpact": "HIGH",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-84894",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-09-30T15:05:21.880556Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "problemTypes": [
              {
                "descriptions": [
                  {
                    "cweId": "CWE-416",
                    "description": "CWE-416 Use After Free",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-09-30T15:03:42.745Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "moxygen",
              "vendor": "Meta Platforms, Inc",
              "versions": [
                {
                  "lessThan": "004123dd24c30dad6b649163575145f240dabc94",
                  "status": "affected",
                  "version": "b24f8e65cb83ebe5f3880cc4e3a4c8f64e1882f9",
                  "versionType": "git"
                }
              ]
            }
          ],
          "dateAssigned": "2026-09-02T00:00:00.000Z",
          "descriptions": [
            {
              "lang": "en",
              "value": "In moxygen before commit 004123dd24c3, MoQSession::dataStreamReadLoop keeps using a stream read handle after reading a FIN, which invalidates the handle under proxygen\u0027s WebTransport API. A remote peer can trigger the stale use by opening a data stream that names an unknown track alias and carries the FIN in the same write."
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "description": "Use After Free (CWE-416)",
                  "lang": "en"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-09-28T18:40:55.707Z",
            "orgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827",
            "shortName": "Meta"
          },
          "references": [
            {
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://www.facebook.com/security/advisories/cve-2026-84894"
            },
            {
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/facebookexperimental/moxygen/commit/004123dd24c30dad6b649163575145f240dabc94"
            }
          ]
        }
      },
      "cveMetadata": {
        "assignerOrgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827",
        "assignerShortName": "Meta",
        "cveId": "CVE-2026-84894",
        "datePublished": "2026-09-28T18:40:55.707Z",
        "dateReserved": "2026-09-02T14:52:36.354Z",
        "dateUpdated": "2026-09-30T15:05:50.817Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



Related by attack behaviour

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.