Temporal Server Schedule exclusion search can cause excessive CPU consumption
Published Sep 21, 2026
7.1
HIGHCVSS 4.0
EPSS 0.27%
Description
Temporal Server did not bound the work performed while searching for a Schedule's next action time. An authenticated caller with namespace write permission could create or update a Schedule that combines a fine-grained cadence with an exclusion calendar that rejects every candidate time, causing the server to evaluate excluded candidates without a per-search work budget. This can consume excessive CPU in Frontend and Schedule worker components. A persisted specification can also cause its backing Schedule Workflow to repeatedly fail and retry, allowing CPU consumption to continue without additional requests until the Schedule is deleted or its backing Workflow is terminated. Repeated or parallel exploitation can deny service. The issue affects availability only; it does not expose or modify Workflow data.
Affected products
-
Affected
- ≥ 1.17.0, ≤ 1.29.7
- ≥ 1.30.0, < 1.30.7
- ≥ 1.31.0, < 1.31.3
Default status is the baseline for the product. Each version can override it (patched versions can be marked unaffected).
| Vendor | Product | Default status | Versions |
|---|---|---|---|
| Temporal Technologies, Inc. | Temporal Server | unaffected | Affected
|
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No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Vendor solution
Upgrade to Temporal Server 1.30.7, 1.31.3, or 1.32.0, as appropriate for the deployed minor release line, and retain a positive scheduler.specMaxIterations value. The fix bounds the number of excluded candidates evaluated by each next-action search and stops the search with an error when the bound is reached. Review and replace or remove Schedule specifications that exceed the configured bound. Setting scheduler.specMaxIterations to zero or a negative value disables the hard bound.
References (5)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-83884 Advisory
- https://github.com/temporalio/temporal/commit/c10c730e53ae394fffaefe44ba3722150fe40720 patch
- https://github.com/temporalio/temporal/pull/11014 patch
- https://github.com/temporalio/temporal/releases/tag/v1.30.7 release-notes
- https://github.com/temporalio/temporal/releases/tag/v1.31.3 release-notes
Change history (0)
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