CVE-2026-8833
June 9, 2026, 2:49 p.m.
8.5
High
Description
Improper neutralization of HTML-encoded characters in the URL validation function in Checkmk <2.5.0p5, <2.4.0p31, <2.3.0p48, and all 2.2.0 versions allows an authenticated user to bypass URL validation and inject malicious URLs such as javascript: URIs, resulting in cross-site scripting when another user interacts with the crafted link.
Product(s) Impacted
| Vendor | Product | Versions |
|---|---|---|
| Checkmk |
|
|
Weaknesses
Common security weaknesses mapped to this vulnerability.
CWE-79
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
*CPE(s)
Affected systems and software identified for this CVE.
| Type | Vendor | Product | Version | Update | Edition | Language | Software Edition | Target Software | Target Hardware | Other Information |
|---|---|---|---|---|---|---|---|---|---|---|
| a | checkmk | checkmk | 2.2.0 | - | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b4 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b5 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b6 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b7 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | b8 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | i1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p10 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p11 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p12 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p13 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p14 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p15 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p16 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p17 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p18 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p19 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p20 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p21 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p22 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p23 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p24 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p25 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p26 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p27 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p28 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p29 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p30 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p31 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p32 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p33 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p34 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p35 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p36 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p37 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p38 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p39 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p4 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p40 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p41 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p42 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p43 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p44 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p45 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p46 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p47 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p5 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p6 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p7 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p8 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.2.0 | p9 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | - | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | b1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | b2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | b3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | b4 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | b5 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | b6 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p10 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p11 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p12 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p13 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p14 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p15 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p16 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p17 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p18 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p19 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p20 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p21 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p22 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p23 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p24 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p25 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p26 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p27 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p28 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p29 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p30 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p31 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p32 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p33 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p34 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p35 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p36 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p37 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p38 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p39 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p4 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p40 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p41 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p42 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p43 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p44 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p45 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p46 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p47 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p5 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p6 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p7 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p8 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.3.0 | p9 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | / | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | - | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | b1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | b2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | b3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | b4 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | b5 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | b6 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p10 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p11 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p12 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p13 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p14 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p15 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p16 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p17 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p18 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p19 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p20 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p21 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p22 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p23 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p24 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p25 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p26 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p27 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p28 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p29 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p30 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p4 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p5 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p6 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p7 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p8 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.4.0 | p9 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | - | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | b1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | b2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | b3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | p1 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | p2 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | p3 | / | / | / | / | / | / |
| a | checkmk | checkmk | 2.5.0 | p4 | / | / | / | / | / | / |
References
Tags
CVSS Score
CVSS Data - 4.0
- Attack Vector: NETWORK
- Attack Complexity: LOW
- Attack Requirements: NONE
- Privileges Required: LOW
- User Interaction: ACTIVE
- Scope:
- Confidentiality Impact: HIGH
- Integrity Impact: HIGH
- Availability Impact: HIGH
- Exploit Maturity: NOT_DEFINED
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/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
Timeline
Published: June 8, 2026, 1:16 p.m.
Last Modified: June 9, 2026, 2:49 p.m.
Last Modified: June 9, 2026, 2:49 p.m.
Status : Analyzed
CVE has been recently published to the CVE List and has been received by the NVD.
More infoSource
*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.