--- title: "CVE-2026-81938: Grafana Mimir - Information Disclosure" description: "Grafana Mimir < 3.1.7 and < 3.2.2 contains a file read vulnerability caused by insufficient validation of http_headers..files and basic_auth.username_file in Alertmanager tenant configurations, letting tenants with config upload permission read arbitrary files on the Alertmanager host by directing receivers to attacker-controlled servers." url: https://panop.io/threat-heartbeat/CVE-2026-81938/ --- # CVE-2026-81938 Grafana Mimir - Information Disclosure Grafana Mimir < 3.1.7 and < 3.2.2 contains a file read vulnerability caused by insufficient validation of http\_headers..files and basic\_auth.username\_file in Alertmanager tenant configurations, letting tenants with config upload permission read arbitrary files on the Alertmanager host by directing receivers to attacker-controlled servers. CVSS base score 7.7 /10 High CISA KEV Not listed Public exploit None known Authentication Required [View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-81938) ## Details Type Information Disclosure Impact File System Read, Information Disclosure CVSS vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N Published 2 November 2026 Updated 3 November 2026 Weakness [CWE-22](https://cwe.mitre.org/data/definitions/22.html) ## Vendor fix Upgrade to Mimir 3.1.7, 3.2.2 or GEM 2.17.20 or later. Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them. ## References - [https://nvd.nist.gov/vuln/detail/CVE-2026-81938](https://nvd.nist.gov/vuln/detail/CVE-2026-81938) - [https://grafana.com/security/security-advisories/cve-2026-81938](https://grafana.com/security/security-advisories/cve-2026-81938) [← All CVEs](https://panop.io/threat-heartbeat/) ## What this record can't tell you - Whether you run the affected software, and where - Whether an attacker can actually reach and exploit it - The misconfigurations that never get a CVE number - What it would cost the business, ranked into what to fix first Panop answers these inside your environment, for this CVE and every other finding. [Book a demo](https://panop.io/demo)