High · CVSS 7.1CVE-2026-16652

Temporal Server Schedule exclusion search can cause excessive CPU consumptionCVE-2026-16652

Answer in brief

CVE-2026-16652 records a High severity (CVSS 7.1) vulnerability in Temporal Server Schedule exclusion search can cause excessive CPU consumption. The current sources do not mark it as known exploited. The current feed maps Temporal Technologies, Inc./go.temporal.io/server (generic), Temporal Technologies, Inc./Temporal Server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 21, 2026Updated Sep 22, 2026Source checked Nov 5, 2026First seen by HOL Sep 21, 2026Material review Sep 22, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.1
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Temporal Technologies, Inc./go.temporal.io/server (generic), Temporal Technologies, Inc./Temporal Server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Temporal Technologies, Inc./go.temporal.io/servergeneric	>=1.17.0 <=1.29.7 \|\| >=1.30.0 <1.30.7 \|\| >=1.31.0 <1.31.3	1.30.7, 1.31.3
Temporal Technologies, Inc./Temporal Servergeneric	1.17.0 \|\| >=1.30.0 <1.30.7 \|\| >=1.31.0 <1.31.3	1.30.7, 1.31.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for Temporal Technologies, Inc./go.temporal.io/server, Temporal Technologies, Inc./Temporal Server.
Review the reported fix. Source-reported 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.

Evidence timeline and material changes

Published upstream
Sep 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 21, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.

Affected scope and exposure questions

The current feed maps Temporal Technologies, Inc./go.temporal.io/server (generic), Temporal Technologies, Inc./Temporal Server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Temporal Technologies, Inc./go.temporal.io/servergeneric	>=1.17.0 <=1.29.7 \|\| >=1.30.0 <1.30.7 \|\| >=1.31.0 <1.31.3	1.30.7, 1.31.3
Temporal Technologies, Inc./Temporal Servergeneric	1.17.0 \|\| >=1.30.0 <1.30.7 \|\| >=1.31.0 <1.31.3	1.30.7, 1.31.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for Temporal Technologies, Inc./go.temporal.io/server, Temporal Technologies, Inc./Temporal Server.

Review the reported fix. Source-reported 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.

Sources and claim methodology

Upstream source description

Quoted source text, attributed separately from HOL analysis.