{"api_version":"1","generated_at":"2026-06-26T20:54:51+00:00","cve":"CVE-2026-47775","urls":{"html":"https://cve.report/CVE-2026-47775","api":"https://cve.report/api/cve/CVE-2026-47775.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-47775","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-47775"},"summary":{"title":"Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decryption","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, the OAuth2 HTTP filter's encrypt()/decrypt() functions use AES-256-CBC without an authentication tag (no HMAC, no AEAD). The /callback endpoint returns HTTP 302 on successful decryption and HTTP 401 on padding failure, creating a padding oracle. An attacker who obtains the encrypted CodeVerifier cookie can recover the plaintext PKCE code_verifier in ~6,200 requests (~100 seconds), then exchange it with a stolen authorization code to obtain the victim's access token. 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Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, the OAuth2 HTTP filter's encrypt()/decrypt() functions use AES-256-CBC without an authentication tag (no HMAC, no AEAD). The /callback endpoint returns HTTP 302 on successful decryption and HTTP 401 on padding failure, creating a padding oracle. An attacker who obtains the encrypted CodeVerifier cookie can recover the plaintext PKCE code_verifier in ~6,200 requests (~100 seconds), then exchange it with a stolen authorization code to obtain the victim's access token. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.8,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-209","description":"CWE-209: Generation of Error Message Containing Sensitive Information","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-327","description":"CWE-327: Use of a Broken or Risky Cryptographic Algorithm","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-06-26T17:23:51.663Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-396h-jpq4-vc7p","tags":["x_refsource_CONFIRM"],"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-396h-jpq4-vc7p"}],"source":{"advisory":"GHSA-396h-jpq4-vc7p","discovery":"UNKNOWN"},"title":"Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decryption"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-47775","datePublished":"2026-06-26T17:23:51.663Z","dateReserved":"2026-05-19T22:36:16.882Z","dateUpdated":"2026-06-26T17:23:51.663Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-26 18:16:59","lastModifiedDate":"2026-06-26 19:50:17","problem_types":["CWE-209","CWE-327","CWE-209 CWE-209: Generation of Error Message Containing Sensitive Information","CWE-327 CWE-327: Use of a Broken or Risky Cryptographic Algorithm"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N","baseScore":6.8,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":1.6,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"47775","Ordinal":"1","Title":"Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decry","CVE":"CVE-2026-47775","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"47775","Ordinal":"1","NoteData":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, the OAuth2 HTTP filter's encrypt()/decrypt() functions use AES-256-CBC without an authentication tag (no HMAC, no AEAD). The /callback endpoint returns HTTP 302 on successful decryption and HTTP 401 on padding failure, creating a padding oracle. An attacker who obtains the encrypted CodeVerifier cookie can recover the plaintext PKCE code_verifier in ~6,200 requests (~100 seconds), then exchange it with a stolen authorization code to obtain the victim's access token. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","Type":"Description","Title":"Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decry"}]}}}