envoyproxy envoy up to 1.35.10/1.36.6/1.37.2/1.38.0 encrypt/decrypt information exposure

Summaryinfo

A vulnerability marked as problematic has been reported in envoyproxy envoy up to 1.35.10/1.36.6/1.37.2/1.38.0. Affected is the function encrypt/decrypt. This manipulation causes information exposure. The identification of this vulnerability is CVE-2026-47775. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in envoyproxy envoy up to 1.35.10/1.36.6/1.37.2/1.38.0. Affected by this vulnerability is the function encrypt/decrypt. The manipulation with an unknown input leads to a information exposure vulnerability. The CWE definition for the vulnerability is CWE-209. The product generates an error message that includes sensitive information about its environment, users, or associated data. As an impact it is known to affect confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-47775 since 05/20/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

Upgrading to version 1.35.11, 1.36.7, 1.37.3 or 1.38.1 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Firewall Software

Vendor

• envoyproxy

Name

• envoy

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.26
• 1.27
• 1.28
• 1.29
• 1.30
• 1.31
• 1.32
• 1.33
• 1.34
• 1.35
• 1.35.0
• 1.35.1
• 1.35.2
• 1.35.3
• 1.35.4
• 1.35.5
• 1.35.6
• 1.35.7
• 1.35.8
• 1.35.9
• 1.35.10
• 1.36
• 1.36.0
• 1.36.1
• 1.36.2
• 1.36.3
• 1.36.4
• 1.36.5
• 1.36.6
• 1.37
• 1.37.0
• 1.37.1
• 1.37.2
• 1.38.0

License

• free

Website

• Product: https://github.com/envoyproxy/envoy/

CPE 2.3info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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