{"id":"CVE-2022-21656","aliases":["BIT-envoy-2022-21656","EUVD-2022-26874","GHSA-c9g7-xwcv-pjx2"],"status":"published","title":"X.509 subjectAltName matching bypass in Envoy","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00672,"percentile":0.52394,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-295","CWE-843"],"published":"2022-02-22T22:25:11Z","modified":"2026-10-28T10:25:07Z","fixes":[{"ecosystem":"Bitnami","package":"envoy","fixed_in":["1.20.2"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Bitnami","package":"envoy","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.20.2"}]}]}],"products":[{"vendor":"envoyproxy","product":"envoy"}],"references":[{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2","tags":["x_refsource_CONFIRM","x_transferred","Issue Tracking","Third Party Advisory","advisory"]},{"url":"https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2022-21656","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/21xxx/CVE-2022-21656.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2022-21656","title":"X.509 subjectAltName matching bypass in Envoy","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","status":"published","published":"2022-02-22T22:25:11Z","modified":"2025-04-23T19:01:38.563Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-295"],"updated_at":"2026-11-02T14:34:29.057251Z"}],"euvd":[{"id":"EUVD-2022-26874","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","status":"published","published":"2022-02-22T22:25:11Z","modified":"2025-04-23T19:01:38Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T20:52:07.453218Z"}],"nvd":[{"id":"CVE-2022-21656","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","status":"published","published":"2022-02-22T23:15:11.223Z","modified":"2026-06-17T04:26:41.863Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-295","CWE-843"],"updated_at":"2026-11-02T14:07:12.711288Z"}],"osv":[{"id":"CVE-2022-21656","title":"X.509 subjectAltName matching bypass in Envoy","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","status":"published","published":"2022-02-22T22:25:11Z","modified":"2026-10-28T10:25:07.585272282Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-295"],"updated_at":"2026-11-02T15:44:23.655778Z"},{"id":"BIT-envoy-2022-21656","title":"X.509 subjectAltName matching bypass in Envoy","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","status":"published","published":"2024-03-06T10:56:05.46Z","modified":"2026-09-10T16:01:31.586916124Z","updated_at":"2026-11-02T15:28:29.563843Z"}]}}