# CVE-2026-16652: Temporal Server Schedule exclusion search can cause excessive CPU consumption

> CVE-2026-16652: Temporal Server Schedule exclusion search can cause excessive CPU consumption. CVSS 7.1 (CVSS 4.0).

Canonical: https://rewindex.com/cve/CVE-2026-16652
Last updated: 2026-09-22T19:40:05Z

- Published: 2026-09-21 11:23 UTC · Updated: 2026-09-22 19:40 UTC · Assigner: Temporal
- CVSS: 7.1 (CVSS 4.0) · Severity: High
- EPSS: 0.47%, 40th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-606

## 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 vendors and products

- Temporal Technologies, Inc.: Temporal Server

## Tracked companies

- [Temporal Cloud](https://rewindex.com/company/temporal-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-16652)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-16652)
- [https://github.com/temporalio/temporal/commit/c10c730e53ae394fffaefe44ba3722150fe40720](https://github.com/temporalio/temporal/commit/c10c730e53ae394fffaefe44ba3722150fe40720)
- [https://github.com/temporalio/temporal/pull/11014](https://github.com/temporalio/temporal/pull/11014)
- [https://github.com/temporalio/temporal/releases/tag/v1.30.7](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/v1.31.3)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-16652 · Markdown: https://rewindex.com/cve/CVE-2026-16652.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-16652 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:05:18.445Z