CVE-2026-3466: Insufficient sanitization of dashboard dashlet title links in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p

Routine

MEDIUM 5.4DOWNGRADE

CVE-2026-3466 is a medium-severity flaw (CVSS 5.4) affecting checkmk. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Insufficient sanitization of dashboard dashlet title links in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p46, Checkmk 2.4.0 before 2.4.0p25, and Checkmk 2.5.0 (beta) before 2.5.0 allows an attacker with dashboard creation privileges to perform stored cross-site scripting (XSS) attacks by tricking a victim into clicking a crafted dashlet title link on a shared dashboard.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 86%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-04-07
Last modified	2026-06-17

Publisher (CNA): Checkmk GmbH · Vendor: checkmk

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-07 13:16 UTCPublished CVE record published
2026-06-17 10:43 UTCUpdated Record last modified

checkmk checkmk DOWNGRADE

Affected: 2.2.0 · 2.2.0 b1 · 2.2.0 b2 · 2.2.0 b3 · 2.2.0 b4 · 2.2.0 b5 · 2.2.0 b6 · 2.2.0 b7

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.2.0 (Debian / Ubuntu)

apt-cache madison checkmk sudo apt install checkmk=<VERSION_BEFORE_2.2.0> sudo apt-mark hold checkmk

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list checkmk sudo dnf downgrade checkmk-<VERSION_BEFORE_2.2.0> sudo dnf versionlock add checkmk

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-2026-3466?

checkmk: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-3466 being exploited?

CVE-2026-3466 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-2026-3466 affect?

CVE-2026-3466 affects checkmk. Severity is medium (CVSS 5.4). Insufficient sanitization of dashboard dashlet title links in Checkmk 2.2.0 (EOL), Checkmk 2.3.0 before 2.3.0p46, Checkmk 2.4.0 before 2.4.0p25, and Checkmk 2.5.0 (beta) before 2.5.0 allows an attacker with dashboard creation privileges to

How urgent is CVE-2026-3466?

Priority 22/100. No elevated risk signals yet.

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References

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