PT-2026-52886 · Undefined · Undefined
Published
2026-06-26
·
Updated
2026-06-26
·
CVE-2026-47775
CVSS v3.1
6.8
Medium
| Vector | AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N |
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.
Fix
Generation of Error Message Containing Sensitive Information
Use of a Broken Cryptographic Algorithm
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Related Identifiers
Affected Products
Undefined