CVE-2026-16652: Temporal Server · Unchecked Input for Loop Condition
Affects Temporal ServerSource CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 1.31.3 or 1.30.7 soon.
Data as of 5 Nov 2026, 00:01 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.31.3, 1.30.7
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 21 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade Temporal Server and go.temporal.io/server to 1.31.3 or 1.30.7.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Temporal Technologies, Inc.Temporal Server | Affected
| Fixed in
|
Gogo.temporal.io/serverpkg:golang/go.temporal.io/serverOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:temporal:temporal:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, restrict namespace write permissions to trusted users to reduce risk. Monitor schedules for unusual configurations that combine fine-grained cadence with exclusion calendars rejecting all times, and remove or correct such schedules to prevent CPU exhaustion.
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.
References
- github.com/temporalio/temporal/pull/11014 (opens in a new tab)
- github.com/temporalio/temporal/commit/c10c730e53ae394fffaefe44ba3722150fe40720 (opens in a new tab)
- github.com/temporalio/temporal/releases/tag/v1.30.7 (opens in a new tab)
- github.com/temporalio/temporal/releases/tag/v1.31.3 (opens in a new tab)