CVE-2026-5724
CWE-306Published: April 10, 2026· Updated: Apr 13, 2026
Official Description
The frontend gRPC server's streaming interceptor chain did not include the authorization interceptor. When a ClaimMapper and Authorizer are configured, unary RPCs enforce authentication and authorization, but the streaming AdminService/StreamWorkflowReplicationMessages endpoint accepted requests without credentials. This endpoint is registered on the same port as WorkflowService and cannot be disabled independently. An attacker with network access to the frontend port could open the replication stream without authentication. Data exfiltration is possible, but only when a configured replication target is correctly configured and the attacker has knowledge of the cluster configuration, as the history service validates cluster IDs and peer membership before returning replication data.
Temporal Cloud is not affected.
Technical Analysis
CVE-2026-5724 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A proof-of-concept (PoC) exploit exists for CVE-2026-5724. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (3)
Quick Facts
Related CVEs (CWE-306)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-5724 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts