Answer in brief
CVE-2026-89140 records a Medium severity (CVSS 6.0) vulnerability in Temporal Server internal completion callbacks are not bound to their namespace, allowing cross-namespace changes to Scheduler V2 schedule state. 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./go.temporal.io/server (generic), Temporal Technologies, Inc./go.temporal.io/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.
CVSS is 6.0. 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.
The current feed maps Temporal Technologies, Inc./go.temporal.io/server (generic), Temporal Technologies, Inc./go.temporal.io/server (generic), Temporal Technologies, Inc./go.temporal.io/server (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Temporal Technologies, Inc./go.temporal.io/servergeneric | >=1.30.0 <1.30.8 | 1.30.8 |
| Temporal Technologies, Inc./go.temporal.io/servergeneric | >=1.31.0 <1.31.4 | 1.31.4 |
| Temporal Technologies, Inc./go.temporal.io/servergeneric | >=1.32.0 <1.32.1 | 1.32.1 |
Published upstream
Oct 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 12, 2026
Temporal Server does not bind internal completion callbacks to the namespace that attached them, which allows an authenticated caller with write permission in one namespace to alter Scheduler V2 schedule state in another namespace. The callback address temporal://internal is reserved for callbacks that Scheduler V2 attaches to the Workflows it starts. In affected releases, any authenticated caller could attach a callback with that address to a Workflow start request, the address was exempt from the component.callbacks.allowedAddresses allowlist, and the History service delivered the callback to the component its token named, in whatever namespace that was, without authorizing the original caller there. When the forged completion matches an action a target schedule is running, the schedule records the action as completed while its Workflow still runs, which can defeat an overlap policy such as SKIP, and passes caller-controlled data to the next scheduled Workflow as its last completion result. A forged failure may also pause a schedule configured to pause on failure. A forgery requires the target namespace identifier, the schedule identifier, and the identity and timing of a running action. No disclosure of Workflow payloads or history was identified. Only namespaces that hold Scheduler V2 schedules can be targeted; Scheduler V2 is off by default, and existing Scheduler V2 schedules remain targets after the settings that create them are turned off.
Quoted source text, attributed separately from HOL analysis.