What’s Vulnerable › Vulnerabilities

CVE-2026-42151: Prometheus Azure AD remote write OAuth client secret exposed via config API

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-04 · updated 2026-09-10
• Weakness: CWE-200

Description

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 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. This issue has been patched in versions 3.5.3 and 3.11.3.

Affected products

• prometheus: from 2.48.0 before 3.5.3; from 3.6.0 before 3.11.3 — fixed in 3.11.3, 3.5.3

How to fix

Upgrade to a fixed version: prometheus 3.11.3, 3.5.3. Check the vendor advisory for mitigations.

References

• https://github.com/prometheus/prometheus/pull/18587
• https://github.com/prometheus/prometheus/pull/18590
• https://github.com/prometheus/prometheus/releases/tag/v3.11.3
• https://github.com/prometheus/prometheus/releases/tag/v3.5.3
• https://github.com/prometheus/prometheus/security/advisories/GHSA-wg65-39gg-5wfj
• https://access.redhat.com/errata/RHSA-2026:25039
• https://access.redhat.com/errata/RHSA-2026:25245
• https://access.redhat.com/errata/RHSA-2026:25504
• https://access.redhat.com/errata/RHSA-2026:34357
• https://access.redhat.com/errata/RHSA-2026:34359
• https://access.redhat.com/errata/RHSA-2026:36651
• https://access.redhat.com/errata/RHSA-2026:36796

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