CVE-2026-65652: temporalio/tchannel-go malformed checksum type 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 validate the one-byte checksum-type field in inbound TChannel call frames. A network peer that can reach a listener can complete the standard initialization handshake and send a call request with an unsupported checksum type. The parser uses that value as an index into a four-entry checksum pool, causing an unrecovered Go panic on the connection read goroutine and terminating 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 0.0.0-20160105034737-a6904155f628 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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