{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-84894", "assignerOrgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827", "state": "PUBLISHED", "assignerShortName": "Meta", "dateReserved": "2026-09-02T14:52:36.354Z", "datePublished": "2026-09-28T18:40:55.707Z", "dateUpdated": "2026-09-30T15:05:50.817Z"}, "containers": {"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'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."}], "problemTypes": [{"descriptions": [{"description": "Use After Free (CWE-416)", "lang": "en"}]}], "providerMetadata": {"orgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827", "shortName": "Meta", "dateUpdated": "2026-09-28T18:40:55.707Z"}, "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"}]}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "CWE-416 Use After Free"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-09-30T15:05:21.880556Z", "id": "CVE-2026-84894", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-30T15:05:50.817Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2026-84894", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-30T15:05:21.880556Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-30T15:03:42.745Z"}}], "cna": {"affected": [{"vendor": "Meta Platforms, Inc", "product": "moxygen", "versions": [{"status": "affected", "version": "b24f8e65cb83ebe5f3880cc4e3a4c8f64e1882f9", "lessThan": "004123dd24c30dad6b649163575145f240dabc94", "versionType": "git"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://www.facebook.com/security/advisories/cve-2026-84894", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/facebookexperimental/moxygen/commit/004123dd24c30dad6b649163575145f240dabc94", "tags": ["x_refsource_MISC"]}], "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'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."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Use After Free (CWE-416)"}]}], "providerMetadata": {"orgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827", "shortName": "Meta", "dateUpdated": "2026-09-28T18:40:55.707Z"}}}, "cveMetadata": {"cveId": "CVE-2026-84894", "state": "PUBLISHED", "dateUpdated": "2026-09-30T15:05:50.817Z", "dateReserved": "2026-09-02T14:52:36.354Z", "assignerOrgId": "4fc57720-52fe-4431-a0fb-3d2c8747b827", "datePublished": "2026-09-28T18:40:55.707Z", "assignerShortName": "Meta"}, "dataVersion": "5.2"}

{"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'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."}], "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"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b24f8e65cb83ebe5f3880cc4e3a4c8f64e1882f9,004123dd24c30dad6b649163575145f240dabc94)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "moxygen", "source": "cna", "vendor": "Meta Platforms, Inc"}, "product": "moxygen", "vendor": "meta_platforms_inc"}], "created": "2026-09-28T21:15:07.765920+00:00", "title": "Use\u2011After\u2011Free in moxygen Data Stream Read Loop Causes Service Crash", "updated": "2026-10-01T04:15:16.822957+00:00", "vendors": ["meta_platforms_inc", "meta_platforms_inc$PRODUCT$moxygen"]}