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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-47775

28
FAUCET Score

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.

First published: Jun 26, 2026Last modified: Jun 26, 2026

Impacted Technologies

VendorProductVersion(s)CPE
>= 1.35.0, < 1.35.11CPE matchmatch criteria
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
>= 1.36.0, < 1.36.7CPE matchmatch criteria
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
>= 1.37.0, < 1.37.3CPE matchmatch criteria
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
>= 1.38.0, < 1.38.1CPE matchmatch criteria
cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.8MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
1.6
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.16%
Probability of exploitation in next 30 days
EPSS Percentile
5.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0016 is in the 9th percentile among its peer group of 707 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.2 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.2 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Patches (1)

github_advisoryworkaround availablevia nvd_reference
View patch

References

github.com / envoyproxy/envoy/security/advisories/GHSA-396h-jpq4-vc7p
ExploitVendor AdvisoryMitigation