Temporal Server compiles a Worker Controller Instance module, go.temporal.io/auto-scaled-workers, into its Worker Service, and that module…
CVE-2026-120091
Temporal Server compiles a Worker Controller Instance module, go.temporal.io/auto-scaled-workers, into its Worker Service, and that module registers a compute provider named k8s whose function is to manage workers running in a Kubernetes cluster. The k8s provider built its Kubernetes client from the client configuration supplied in the caller's request rather than from operator configuration, and building and using that client could run a command of the caller's choosing on the Worker Service host, under the account the server process runs as. Two frontend operations reach the provider. CreateWorkerDeploymentVersion requires a namespace write role. ValidateWorkerDeploymentVersionComputeConfig is registered as a read-only namespace operation, so an authenticated caller holding only a read role in a single namespace can reach the provider through it, and that route does not require a worker deployment to already exist. Execution happens while the submitted configuration is validated, so no scaling decision, task arrival, or unusual request sequence is required. Because the Worker Service process holds the persistence credentials for every namespace in the cluster and the cluster's…
Assessment
- CVSS
- 8.7 (v4.0)
- Severity
- High
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 3 November 2026
- Last updated
- 3 November 2026
- Affected
- Temporal Technologies, Inc. · Temporal Server
- Assigner
- Temporal
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
At the source
References
- https://github.com/temporalio/temporal/releases/tag/v1.32.2
- https://github.com/temporalio/temporal/releases/tag/v1.31.5
- https://github.com/temporalio/temporal-auto-scaled-workers/pull/165
- https://github.com/temporalio/temporal/pull/12843
- https://www.cve.org/CVERecord?id=CVE-2026-89139
- https://nvd.nist.gov/vuln/detail/CVE-2026-120091
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