Temporal Server does not bind a workflow-history pagination token to the namespace and workflow named in the request that presents it.
CVE-2026-87857
Temporal Server does not bind a workflow-history pagination token to the namespace and workflow named in the request that presents it. GetWorkflowExecutionHistory and GetWorkflowExecutionHistoryReverse authorize the caller against the namespace in the request, then select history from the branch recorded inside the caller-supplied nextpagetoken. The normal history continuation carries a run identifier, event bounds, a persistence cursor, and a branch token, but no namespace or workflow identity, and it is serialized as unauthenticated protobuf bytes. An authenticated caller holding read permission on one namespace, together with a genuine non-final continuation issued earlier for a workflow in a second namespace, can submit that continuation with a request naming the first namespace and receive the second namespace's workflow history, provided the supplied workflow identifier selects the same History shard as the continuation's branch. No workflow with the supplied identifier needs to exist. Because the token is unauthenticated, a holder can also advance its event range and clear its persistence cursor, which returns history events created after that caller's current credential no…
Assessment
- CVSS
- 5.3 (v4.0)
- Severity
- Medium
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 9 November 2026
- Last updated
- 9 November 2026
- Affected
- Temporal Technologies, Inc. · Temporal Server
- Assigner
- Temporal
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
At the source
References
- https://github.com/temporalio/temporal/blob/v1.0.0/service/frontend/workflowHandler.go#L602-L740
- https://github.com/temporalio/temporal/pull/11723
- https://github.com/temporalio/temporal/commit/ceb1cc1071b1fd37f8a2cd8ef5ed3e4333245cc2
- https://github.com/temporalio/temporal/pull/11919
- https://github.com/temporalio/temporal/commit/4b02728735450dd60eaff9a5d0dc8e11fc8a4b13
- https://github.com/temporalio/temporal/pull/12039
- https://github.com/temporalio/temporal/commit/c82a2d228e7287b1d283a55477f40a1a48481010
- https://github.com/temporalio/temporal/pull/12040
- https://github.com/temporalio/temporal/commit/690b53103e11982de5f9187f722a0e0d3780028d
- https://github.com/temporalio/temporal/releases/tag/v1.30.7
- https://github.com/temporalio/temporal/releases/tag/v1.31.3
- https://github.com/temporalio/temporal/releases/tag/v1.32.0
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