CVE-2026-33378: Using the $__timeGroup macro, one can achieve an OOM by overloading the server

Routine

MEDIUM 6.5UPGRADE

CVE-2026-33378 is a medium-severity flaw (CVSS 6.5) affecting grafana. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Using the $__timeGroup macro, one can achieve an OOM by overloading the server. This requires a SQL datasource. If the server is set up to auto-restart, the impact is minimal or non-existent, as the attack can take upwards of half an hour to crash the server.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 74%)
CISA exploited list	No
Weakness	CWE-400
Published	2026-05-13
Last modified	2026-10-26

Publisher (CNA): Grafana Labs · Vendor: grafana

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-13 20:16 UTCPublished CVE record published
2026-10-26 14:10 UTCUpdated Record last modified

grafana grafana UPGRADE

Affected: >= 8.0.0 and < 11.6.14 · >= 12.0.0 and < 12.2.8 · >= 12.3.0 and < 12.3.6 · >= 12.4.0 and < 12.4.3 · 11.6.14 · 11.6.14 security01 · 12.2.8 · 12.2.8 security01

Fixed in: 11.6.14, 12.2.8, 12.3.6, 12.4.3

Safe to downgrade to: a release before 8.0.0

1. Check installed version

apt-cache policy grafana || rpm -q grafana || grafana --version

2. UPGRADE to 11.6.14 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade grafana

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade grafana

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 8.0.0 (Debian / Ubuntu)

apt-cache madison grafana sudo apt install grafana=<VERSION_BEFORE_8.0.0> sudo apt-mark hold grafana

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list grafana sudo dnf downgrade grafana-<VERSION_BEFORE_8.0.0> sudo dnf versionlock add grafana

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33378?

grafana: upgrade to 11.6.14, 12.2.8, 12.3.6, 12.4.3. Exact commands for each OS are on this page.

Is CVE-2026-33378 being exploited?

CVE-2026-33378 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33378 affect?

CVE-2026-33378 affects grafana. Severity is medium (CVSS 6.5). Using the $__timeGroup macro, one can achieve an OOM by overloading the server. This requires a SQL datasource. If the server is set up to auto-restart, the impact is minimal or non-existent, as the attack can take upwards of half an hour t

How urgent is CVE-2026-33378?

Priority 29/100. No elevated risk signals yet.

Software pages

Grafana vulnerabilities

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References

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