CVE-2026-65653: temporalio/tchannel-go zero-chunk call fragment causes process termination

Severity: high (CVSS 8.7 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-21 · updated 2026-09-22
Weakness: CWE-129

Description

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

How to fix

Upgrade to a fixed version: Temporal Technologies, Inc. temporalio/tchannel-go 1.22.1-0.20260720194454-0cb017f6870a. Check the vendor advisory for mitigations.

References

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