CVE-2026-47775: Envoy OAuth2 Filter: Padding Oracle via AES-256-CBC Cookie Decryption
envoyproxy · envoy
Affected: envoyproxy · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 12% of scored CVEs
DescriptionCVE.org
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 products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- envoyproxy · envoy>= 1.38.0, < 1.38.1; >= 1.37.0, < 1.37.3; >= 1.36.0, < 1.36.7; < 1.35.11
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- envoyproxy
- Published
- June 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-47775 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.