{"api_version":"1","generated_at":"2026-07-23T20:59:02+00:00","cve":"CVE-2021-43826","urls":{"html":"https://cve.report/CVE-2021-43826","api":"https://cve.report/api/cve/CVE-2021-43826.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-43826","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-43826"},"summary":{"title":"CVE-2021-43826","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions of Envoy a crash occurs when configured for :ref:`upstream tunneling <envoy_v3_api_field_extensions.filters.network.tcp_proxy.v3.TcpProxy.tunneling_config>` and the downstream connection disconnects while the the upstream connection or http/2 stream is still being established. There are no workarounds for this issue. 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Users are advised to upgrade."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","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:H","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-416: Use After Free"}]}]},"references":{"reference_data":[{"name":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-cmx3-fvgf-83mf","refsource":"CONFIRM","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-cmx3-fvgf-83mf"},{"name":"https://github.com/envoyproxy/envoy/commit/ce0ae309057a216aba031aff81c445c90c6ef145","refsource":"MISC","url":"https://github.com/envoyproxy/envoy/commit/ce0ae309057a216aba031aff81c445c90c6ef145"}]},"source":{"advisory":"GHSA-cmx3-fvgf-83mf","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2022-02-22 23:15:00","lastModifiedDate":"2022-03-02 15:23:00","problem_types":["CWE-416"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:M/Au:N/C:N/I:N/A:P","accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL","baseScore":4.3},"severity":"MEDIUM","exploitabilityScore":8.6,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionStartIncluding":"1.21.0","versionEndExcluding":"1.21.1","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionStartIncluding":"1.20.0","versionEndExcluding":"1.20.2","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionStartIncluding":"1.19.0","versionEndExcluding":"1.19.3","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionEndExcluding":"1.18.6","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"43826","Ordinal":"221331","Title":"CVE-2021-43826","CVE":"CVE-2021-43826","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"43826","Ordinal":"1","NoteData":"** RESERVED ** This candidate has been reserved by an organization or individual that will use it when announcing a new security problem. When the candidate has been publicized, the details for this candidate will be provided.","Type":"Description","Title":null}]}}}