CVE-2026-33378
Description
A flaw was found in Grafana. A remote attacker with authenticated access to a SQL datasource can exploit a vulnerability in the $__timeGroup macro. By sending specially crafted queries, an attacker can cause an Out of Memory (OOM) error, leading to the Grafana server crashing and resulting in a Denial of Service (DoS). This can disrupt the availability of the Grafana instance.
Statement
A moderate severity denial of service flaw was found in Grafana. A remote attacker with authenticated access to a Grafana instance that has a SQL data source configured can send specially crafted queries that abuse the $__timeGroup macro to exhaust memory on the server, causing an out-of-memory (OOM) crash that disrupts the availability of the Grafana instance. Exploitation requires valid credentials and a configured SQL data source, and the attack can take upwards of half an hour to crash the server, so the practical impact is reduced on deployments configured to automatically restart the service. This issue affects the grafana12.4, grafana13.1, and grafana13.2 components shipped in Red Hat Hardened Images (hummingbird-1), where a fix is being pursued; the hi/grafana container image distributed for hummingbird-1 is not affected because the vulnerable component is not present. Red Hat rates this flaw Moderate (CVSS 6.5, CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), consistent with the upstream Medium severity rating.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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