CVE-2026-33456: checkmk gmbh checkmk Improper Neutralization of Delimiters
CVSS: 7.6v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-33456
Published 10-04-2026Last modified 14-04-2026
Vulnerability summary
CVE-2026-33456 is a high (CVSS 7.6) Improper Neutralization of Delimiters vulnerability in checkmk gmbh checkmk. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities.
CVSS score
7.6/10
010
High · v3.1 (NVD)EPSS score
0.34%
0%100%
Low · +0.14 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-04-2026PublishedVulnerability first disclosed.
- 14-04-2026Last modifiedVulnerability information updated.
Description
Livestatus injection in the notification test mode in Checkmk <2.5.0b4 and <2.4.0p26 allows an authenticated user with access to the notification test page to inject arbitrary Livestatus commands via a crafted service description.
CVSS metrics
5 scores · 3 sources · 2 versionsMedium 5.1Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
- NVDNIST5.1MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/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
High 7.6Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:HSourcesAll 2 agree
- OSV · UbuntuEcosystem advisory · calculated7.6HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
EPSS trend
Probability
0.34%
Chance of exploitation in the next 30 days
Percentile
26%
Versus all other CVEs
30-day change
+0.14 pp
From 0.20% on 21-09-2026
21-09-202621-10-2026
EPSS score0.34%
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
- checkmk2.4.0 | 2.4.0:b1 | 2.4.0:b2 | 2.4.0:b3 | 2.4.0:b4 | 2.4.0:b5 | 2.4.0:b6 | 2.4.0:p1 | 2.4.0:p10 | 2.4.0:p11 | 2.4.0:p12 | 2.4.0:p13 | 2.4.0:p14 | 2.4.0:p15 | 2.4.0:p16 | 2.4.0:p17 | 2.4.0:p18 | 2.4.0:p19 | 2.4.0:p2 | 2.4.0:p20 | 2.4.0:p21 | 2.4.0:p22 | 2.4.0:p23 | 2.4.0:p24 | 2.4.0:p25 | 2.4.0:p3 | 2.4.0:p4 | 2.4.0:p5 | 2.4.0:p6 | 2.4.0:p7 | 2.4.0:p8 | 2.4.0:p9 | 2.5.0:b1 | 2.5.0:b2 | 2.5.0:b3
Checkmk gmbh1 product
- checkmk≥ 2.5.0, < 2.5.0b4 | ≥ 2.4.0, < 2.4.0p26
Ubuntu1 product
- check-mkAll versions (No fix recorded)
3 vendors · 3 products