Vulnerability from bitnami_vulndb
Published
2026-06-30 23:39
Modified
2026-07-01 00:07
Summary
Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decryption
Details

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.

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "envoy",
        "purl": "pkg:bitnami/envoy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.35.0"
            },
            {
              "fixed": "1.35.11"
            },
            {
              "introduced": "1.36.0"
            },
            {
              "fixed": "1.36.7"
            },
            {
              "introduced": "1.37.0"
            },
            {
              "fixed": "1.37.3"
            },
            {
              "introduced": "1.38.0"
            },
            {
              "fixed": "1.38.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47775"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "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\u0027s 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\u0027s access token. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.",
  "id": "BIT-envoy-2026-47775",
  "modified": "2026-07-01T00:07:50.168Z",
  "published": "2026-06-30T23:39:29.055Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-396h-jpq4-vc7p"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47775"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decryption"
}


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