CVE-2026-65653

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.

References

• https://github.com/temporalio/tchannel-go/blob/8706a1ab5f617efd79dace7ab2d1d80cc1881df0/fragmenting_reader.go#L256-L308
• https://github.com/temporalio/tchannel-go/commit/0cb017f6870a8420695abeb9a4560d39dadc4e2e
• https://github.com/temporalio/tchannel-go/commit/1dcfa67262ecd56a24f12940f4082549190cb5d1
• https://github.com/temporalio/tchannel-go/commit/8d8ca17342b3620d3a6d5c1a825145595e7588ff
• https://github.com/temporalio/tchannel-go/pull/14