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GO-2026-6090

Limit handshake messages we are willing to accept post-handshake in crypto/tls

Quick fix

GO-2026-6090 — stdlib: upgrade to the fixed version with the command below.

go get stdlib@v1.25.13

Details

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.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go / stdlib

Introduced in: 0 Fixed in: 1.25.13

Fix go get stdlib@v1.25.13

References

https://go.dev/issue/80528 [REPORT]
https://go.dev/cl/804261 [FIX]
https://groups.google.com/g/golang-announce/c/94pEornpRlI [WEB]