CVE-2026-5724
MEDIUMMissing Authentication on Streaming gRPC Replication Endpoint
Title source: cnaExploitation Summary
EIP tracks 1 public exploit for CVE-2026-5724. PoCs published by tibrn.
AI-analyzed exploit summary The repository contains a functional exploit PoC for CVE-2026-5724, demonstrating an authentication bypass in Temporal's frontend gRPC service. The exploit leverages a missing authorization interceptor in the streaming gRPC chain to access privileged admin endpoints without credentials.
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.
Exploits (1)
The repository contains a functional exploit PoC for CVE-2026-5724, demonstrating an authentication bypass in Temporal's frontend gRPC service. The exploit leverages a missing authorization interceptor in the streaming gRPC chain to access privileged admin endpoints without credentials.
References (3)
Scores
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:L/SI:N/SA:N/S:N/AU:N/R:U/RE:L