CVE-2026-5199

A writer role user in an attacker-controlled namespace could signal, delete, and reset workflows or activities in a victim namespace on the same cluster. Exploitation requires the attacker to know or guess specific victim workflow IDs and, for signal operations, signal names. This was due to a bu...

CVE-2026-5199

The CVE-2026-5199 issue arises from a bug in Temporal Server v1.29.0 where a writer in an attacker-controlled namespace could signal, delete, or reset workflows/activities in a victim namespace on the same cluster. The root cause is that the batch activity validated the victim namespace ID but di...