How severe is CVE-2026-33276?

CVE-2026-33276 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-33276 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33276?

CVE-2026-33276 affects Checkmk. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33276?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-33276 have an EU (EUVD) identifier?

Yes. CVE-2026-33276 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17429.

When was CVE-2026-33276 published?

CVE-2026-33276 was published on 2026-03-31 and last updated on 2026-06-17.

CVE-2026-33276

CVE-2026-33276 is a medium-severity vulnerability in Checkmk with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v4: 8.6
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17429
Weakness: CWE-79
Affected product: Checkmk
Published: 2026-03-31
Last modified: 2026-06-17

Description

Stored cross-site scripting (XSS) in Checkmk 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create hosts or services to execute arbitrary JavaScript in the browsers of other users performing searches in the Unified Search feature.

Frequently asked questions

What is CVE-2026-33276?: Stored cross-site scripting (XSS) in Checkmk 2.5.0 (beta) before 2.5.0b2 allows authenticated users with permission to create hosts or services to execute arbitrary JavaScript in the browsers of other users performing searches in the Unified Search feature.
How severe is CVE-2026-33276?: CVE-2026-33276 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-33276 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33276?: CVE-2026-33276 affects Checkmk. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33276?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33276 have an EU (EUVD) identifier?: Yes. CVE-2026-33276 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17429.
When was CVE-2026-33276 published?: CVE-2026-33276 was published on 2026-03-31 and last updated on 2026-06-17.

References

https://checkmk.com/werk/19525

Affected products (1)

cpe:2.3:a:checkmk:checkmk:2.5.0:b1:*:*:*:*:*:*

More vulnerabilities in Checkmk

CVE-2022-46836 — Critical (CVSS 9.1): PHP code injection in watolib auth.php and hosttags.php in Tribe29's Checkmk <= 2.1.0p10, Checkmk <= 2.0.0p27, and…
CVE-2026-24096 — High (CVSS 8.8): Insufficient permission validation on multiple REST API Quick Setup endpoints in Checkmk 2.5.0 (beta) before version…
CVE-2025-32918 — High (CVSS 8.8): Improper neutralization of Livestatus command delimiters in autocomplete endpoint within the RestAPI of Checkmk…
CVE-2025-1712 — High (CVSS 8.8): Argument injection in special agent configuration in Checkmk <2.4.0p1, <2.3.0p32, <2.2.0p42 and 2.1.0 allows…
CVE-2025-32917 — High (CVSS 8.8): Privilege escalation in jar_signature agent plugin in Checkmk versions <2.4.0b7 (beta), <2.3.0p32, <2.2.0p42, and…
CVE-2024-38865 — High (CVSS 8.8): Improper neutralization of livestatus command delimiters in a specific endpoint within RestAPI of Checkmk prior to…

All CVEs affecting Checkmk →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →