CVE-2026-56862

Description

Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely.

CVSS Vector

References

• https://go.dev/cl/804261
• https://go.dev/issue/80528
• https://groups.google.com/g/golang-announce/c/94pEornpRlI
• https://pkg.go.dev/vuln/GO-2026-6090