Security readout for executives and security teams
Plain-English summary
An authenticated Grafana user can send a crafted dashboard query that forces the server to consume all available memory, eventually crashing it. The attack takes roughly half an hour, and if Grafana is set to auto-restart the disruption is minor. It affects specific Grafana OSS builds that use a SQL data source.
Executive priority
Moderate priority. Plan a scheduled upgrade during the next maintenance window. Not an emergency: no data loss, no known active exploitation, and auto-restart environments experience minimal disruption. Treat as standard patch hygiene for observability tooling.
Technical view
CVE-2026-33378 is a CWE-400 resource-exhaustion flaw in Grafana OSS. Supplying a negative interval to the $__timeGroup macro on a SQL data source triggers unbounded processing that drives the server toward out-of-memory. CVSS 3.1 is 6.5 (AV:N/AC:L/PR:L/UI:N/A:H). Only availability is impacted; confidentiality and integrity are not affected per the vendor advisory.
Likely exposure
Grafana OSS instances running the listed versions with at least one SQL data source configured and reachable by authenticated users. Exposure is highest where Grafana is internet-exposed, shared broadly across teams, or lacks auto-restart. Internal-only deployments with hardened auth and process supervision see reduced practical exposure.
Exploitation context
No KEV listing and no public exploitation reports referenced in the source bundle. Attack requires low-privileged authenticated access and takes up to about 30 minutes to crash the server, per the vendor description. Impact is limited to availability; auto-restart configurations further reduce observable impact.
Researcher notes
Root cause is a negative interval reaching $__timeGroup macro expansion against a SQL data source, producing runaway resource use consistent with CWE-400. Availability-only impact aligns with CVSS A:H, C:N, I:N. Validate by comparing installed build to the vendor's affected version list; the advisory URL is the authoritative source for fixed versions and any mitigations.
Mitigation direction
- Upgrade Grafana OSS to a fixed release per the Grafana security advisory.
- Restrict SQL data source query permissions to trusted roles only.
- Ensure Grafana runs under a supervisor that auto-restarts on crash.
- Limit Grafana network exposure to authenticated internal users where possible.
- Monitor Grafana memory usage and alert on sustained growth.
Validation and detection
- Inventory Grafana OSS versions and compare against the advisory's affected list.
- Identify instances with SQL data sources enabled and enumerate users with query access.
- Review Grafana logs and host metrics for unexplained memory spikes or restarts.
- Confirm process supervision (systemd, Kubernetes, container runtime) restarts Grafana on OOM.
- Re-test dashboards after upgrade to confirm functionality and stable memory.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-400: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-33378 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6GRAFANAVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://grafana.com/security/security-advisories/cve-2026-33378CVE reference, GRAFANA · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.