ISTIO-SECURITY-2025-003

CVEs reported by Envoy.

Dec 3, 2025

Disclosure Details
CVE(s)CVE-2025-66220
CVE-2025-64527
CVE-2025-64763
CVSS Impact Score8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Affected Releases1.28.0
1.27.0 to 1.27.3
1.26.0 to 1.26.6

CVE

Envoy CVEs

Am I Impacted?

If you are using Istio to accept WebSocket traffic, you are potentially vulnerable to request smuggling from early data after the CONNECT upgrade. You may also be vulnerable if you are using custom certificates with OTHERNAME SANs or custom JWT authentication with remote JWKS fetching using EnvoyFilter.