CVE-2026-5724

CVE-2026-5724 is a medium-severity vulnerability with a CVSS 4.0 base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

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. The fix was applied per release line: it is present in 1.28.4, 1.29.6, 1.30.4, 1.31.2, and 1.32.0 and later releases on each line. Releases 1.31.0 and 1.31.1 do not contain the fix and are affected. Temporal Cloud is not affected.

Frequently asked questions

What is CVE-2026-5724?
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. The fix was applied per release line: it is present in 1.28.4, 1.29.6, 1.30.4, 1.31.2, and 1.32.0 and later releases on each line. Releases 1.31.0 and 1.31.1 do not contain the fix and are affected. Temporal Cloud is not affected.
How severe is CVE-2026-5724?
CVE-2026-5724 has a CVSS 4.0 base score of 6.3, rated medium severity.
Is CVE-2026-5724 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-5724?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5724 have an EU (EUVD) identifier?
Yes. CVE-2026-5724 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21607.
When was CVE-2026-5724 published?
CVE-2026-5724 was published on 2026-04-10 and last updated on 2026-07-08.

References

Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities

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