Prometheus Azure AD remote write OAuth client secret exposed via config API
### Impact Users who use Azure AD remote write with OAuth authentication are impacted. The `client_secret` field in the Azure AD remote write OAuth configuration (`storage/remote/azuread`) was typed as `string` instead of `Secret`. Prometheus redacts fields of type `Secret` when serving the configuration via the `/-/config` HTTP API endpoint. Because the field was a plain string, the Azure OAuth client secret was exposed in plaintext to any user or process with access to that endpoint. ### Patches The problem has been patched by changing `ClientSecret` in `OAuthConfig` to `Secret`. Users should upgrade to 3.11.3 or 3.5.3 LTS. ### Workarounds Users who can not upgrade can switch to Managed Identity or Workload Identity authentication for Azure AD remote write, which do not involve a client secret.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-42151US | —OT elevated | — | ||
Prometheus is an open-source monitoring system and time series database. Prior to versions 3.5.3 and 3.11.3, the client_secret field in the Azure AD remote write OAuth configuratio… | ||||
references
External citations — patches, advisories, analysis.
- https://access.redhat.com/errata/RHSA-2026:25039WEB
- https://access.redhat.com/errata/RHSA-2026:25245WEB
- https://access.redhat.com/errata/RHSA-2026:25504WEB
- https://access.redhat.com/errata/RHSA-2026:34357WEB
- https://access.redhat.com/errata/RHSA-2026:34359WEB
- https://access.redhat.com/errata/RHSA-2026:36651WEB
- https://access.redhat.com/errata/RHSA-2026:36796WEB
- https://access.redhat.com/errata/RHSA-2026:36797WEB
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