CVE-2026-33374: Unbounded memory allocation in the Prometheus rule conversion API

Severity: medium (CVSS 6.5 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: 2026-10-13 · updated 2026-10-16
Weakness: CWE-400

Description

The Prometheus rule conversion API endpoints in Grafana do not limit request body size, allowing authenticated users to trigger unbounded memory allocations that can crash the server through out-of-memory conditions.

Affected products

Grafana: from 12.0.0 through 12.3.11; from 12.4.0 before 12.4.13; from 13.0.0 before 13.0.11; from 13.1.0 before 13.1.8; from 13.2.0 before 13.2.4 — fixed in 12.4.13, 13.0.11, 13.1.8, 13.2.4

How to fix

Upgrade to a fixed version: Grafana 12.4.13, 13.0.11, 13.1.8, 13.2.4. Check the vendor advisory for mitigations.

References

https://grafana.com/security/security-advisories/cve-2026-33374

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