{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21435", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2025-12-29T03:00:29.275Z", "datePublished": "2026-02-12T18:22:58.098Z", "dateUpdated": "2026-02-12T18:24:49.233Z"}, "containers": {"cna": {"title": "webtransport-go CloseWithError can block indefinitely", "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "lang": "en", "description": "CWE-400: Uncontrolled Resource Consumption", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}], "references": [{"name": "https://github.com/quic-go/webtransport-go/security/advisories/GHSA-px4r-g4p3-hhqv", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/quic-go/webtransport-go/security/advisories/GHSA-px4r-g4p3-hhqv"}, {"name": "https://github.com/quic-go/webtransport-go/releases/tag/v0.10.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/quic-go/webtransport-go/releases/tag/v0.10.0"}], "affected": [{"vendor": "quic-go", "product": "webtransport-go", "versions": [{"version": "< 0.10.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-02-12T18:24:49.233Z"}, "descriptions": [{"lang": "en", "value": "webtransport-go is an implementation of the WebTransport protocol. Prior to v0.10.0, an attacker can cause a denial of service in webtransport-go by preventing or indefinitely delaying WebTransport session closure. A malicious peer can withhold QUIC flow control credit on the CONNECT stream, blocking transmission of the WT_CLOSE_SESSION capsule and causing the close operation to hang. This vulnerability is fixed in v0.10.0."}], "source": {"advisory": "GHSA-px4r-g4p3-hhqv", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "webtransport-go is an implementation of the WebTransport protocol. Prior to v0.10.0, an attacker can cause a denial of service in webtransport-go by preventing or indefinitely delaying WebTransport session closure. A malicious peer can withhold QUIC flow control credit on the CONNECT stream, blocking transmission of the WT_CLOSE_SESSION capsule and causing the close operation to hang. This vulnerability is fixed in v0.10.0."}], "id": "CVE-2026-21435", "lastModified": "2026-02-12T19:15:51.503", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-02-12T19:15:51.503", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/quic-go/webtransport-go/releases/tag/v0.10.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/quic-go/webtransport-go/security/advisories/GHSA-px4r-g4p3-hhqv"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}