CVE-2026-8833
Last modified
CVE-2026-8833 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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.. EPSS estimates a 0.14% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
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
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Checkmk | Checkmk | 2.2.0 |
| Checkmk | Checkmk | 2.3.0 |
| Checkmk | Checkmk | 2.4.0 |
| Checkmk | Checkmk | 2.5.0 |
References
- https://checkmk.com/werk/20002Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-8833?
How severe is CVE-2026-8833?
How do I fix CVE-2026-8833?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-8825The Elementor Website Builder WordPress plugin before 4.1.4…4.9
- CVE-2026-8827The AddressRepository::getSqlQuery() method constructs a dat…8.2
- CVE-2026-8828A lack of authorization validation in version 1.0.0 or later…8.8
- CVE-2026-8829HTML::Entities versions before 3.84 for Perl read freed heap…7.5
- CVE-2026-8830A flaw was found in Keycloak. An authenticated user can bypa…4.3
- CVE-2026-8832The WPCode - Insert Headers and Footers + Custom Code Snippe…8.8
- CVE-2026-8834IBM HTTP Server 8.5, and 9.0 contains a buffer overflow vuln…8
- CVE-2026-8835IBM HTTP Server 8.5, and 9.0 is vulnerable to invalid pointe…7.3
- CVE-2026-8836A vulnerability was found in lwIP up to 2.2.1. Affected is t…9.8
- CVE-2026-8837The WP Iframe Geo Style for Amazon affiliates plugin for Wor…6.4
- CVE-2026-8838Unsafe use of Python's eval() on server-received data in the…9.8
- CVE-2026-8839The MapPress Maps for WordPress plugin for WordPress is vuln…5.3
Are you affected by CVE-2026-8833?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST