CVE-2026-33276: checkmk gmbh checkmk Cross-site Scripting
CVSS: 8.6v4.0HighAnalyzed
AliasesUBUNTU-CVE-2026-33276
Published 31-03-2026Last modified 31-03-2026
Vulnerability summary
CVE-2026-33276 is a high (CVSS 8.6) Cross-site Scripting vulnerability in checkmk gmbh checkmk. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.1% of scored vulnerabilities.
CVSS score
8.6/10
010
High · v4.0 (CVE.org)EPSS score
0.23%
0%100%
Low · +0.09 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 31-03-2026PublishedVulnerability first disclosed.
- 31-03-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 3 sources · 2 versionsHigh 8.6Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:L/SA:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated8.6HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:L/SA:N
- NVDNIST8.6HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Medium 5.4Preferred score · OSV · Ubuntu (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NSourcesAll 2 agree
- NVDNIST5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
+0.09 pp
From 0.14% on 21-09-2026
21-09-202621-10-2026
EPSS score0.23%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Checkmk1 product
- checkmk2.5.0:b1
Checkmk gmbh1 product
- checkmk≥ 2.5.0b1, < 2.5.0b2
Ubuntu1 product
- check-mkAll versions (No fix recorded)
3 vendors · 3 products