CVE-2026-65653: Temporal Technologies, Inc Temporalio/tchannel-Go

High severity, CVSS 8.7. EPSS: 0.7% chance of exploitation in the next 30 days.

github.com/temporalio/tchannel-go did not reject TChannel call fragments containing checksum metadata but no length-prefixed argument chunks. The fragment reader left its chunk slice empty and then unconditionally selected the first element. A network peer can supply such a malformed call fragment, including as a direct initial call request after completing the standard initialization handshake. On that inbound path, the resulting unrecovered Go slice-bounds panic occurs on a library-created dispatch goroutine and terminates the hosting process. This allows remote denial of service against applications that expose the listener to untrusted peers. The impact is limited to availability; no confidentiality or integrity impact was identified.

Affected products

• Temporal Technologies, Inc Temporalio/tchannel-Go: from 0.0.0-20150531204735-8d8ca17342b3, before 1.22.1-0.20260720194454-0cb017f6870a (fixed in 1.22.1-0.20260720194454-0cb017f6870a)

Published 2026-09-21. Last modified 2026-09-22.