cvedb.io
CVE-2026-47775
MEDIUM · CVSS 6.8
EPSS exploitation probability: 0%
Published 2026-06-26T18:16:59.350 · Last modified 2026-06-29T18:10:33.463

Summary

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.

Affected products

envoyproxy — envoy

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.