CVE-2026-56862

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Go standard librarycrypto/tls0 < 1.25.13affected
Go standard librarycrypto/tls1.26.0-0 < 1.26.6affected
Go standard librarycrypto/tls1.27.0-0 < 1.27.0-rc.3affected

Weaknesses

  • CWE-770: Allocation of Resources Without Limits or Throttling

References