Bug 2538032 (CVE-2026-65653)

Summary: CVE-2026-65653 github.com/temporalio/tchannel-go: github.com/temporalio/tchannel-go: Denial of Service via malformed TChannel call fragments
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: blitton, mbarnett
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in github.com/temporalio/tchannel-go. A remote attacker can exploit this by sending a specially crafted TChannel call fragment that contains checksum metadata but lacks length-prefixed argument chunks. This can lead to a Go slice-bounds panic, causing the hosting process to terminate and resulting in a denial of service (DoS). The impact is limited to availability, with no confidentiality or integrity impact identified.
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Description OSIDB Bzimport 2026-09-22 16:40:54 UTC 
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.