CVE-2026-65652: temporal technologies, inc. temporalio/tchannel-go Improper Validation of Array Index

Vulnerability summary

CVE-2026-65652 is a high (CVSS 8.7) Improper Validation of Array Index vulnerability in temporal technologies, inc. temporalio/tchannel-go. EPSS estimates a 0.71% chance of exploitation in the next 30 days, higher than 52.6% of scored vulnerabilities.

Timeline

1. 21-09-2026
   PublishedVulnerability first disclosed.
2. 21-09-2026
   Last modifiedVulnerability information updated.

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.

• CWE-129Improper Validation of Array IndexThe product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.