CVE-2026-47775: 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…

PriorityP337medium6.8CVSS 3.1

AVNACHPRNUIRSUCHIHAN

EPSS

0.22%

12.3th percentile

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

8 ranges

Vendor	Product	Version range	Fixed in
envoyproxy	envoy	< 1.35.11	1.35.11
envoyproxy	envoy	—	—
envoyproxy	envoy	—	—
envoyproxy	envoy	—	—
envoyproxy	envoy	>= 1.35.0 < 1.35.11	1.35.11
envoyproxy	envoy	>= 1.36.0 < 1.36.7	1.36.7
envoyproxy	envoy	>= 1.37.0 < 1.37.3	1.37.3
envoyproxy	envoy	>= 1.38.0 < 1.38.1	1.38.1

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.