UBUNTU-CVE-2026-8833

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Source

https://ubuntu.com/security/CVE-2026-8833

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-8833.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-8833

Upstream

CVE-2026-8833

Published

2026-06-08T13:16:00Z

Modified

2026-06-11T13:02:02Z

Severity

8.5 (High) CVSS_V4 - 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 CVSS Calculator
5.4 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

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.

References

Affected packages

Ubuntu:Pro:16.04:LTS / check-mk

Package

Name: check-mk
Purl: pkg:deb/ubuntu/check-mk?arch=source&distro=esm-apps%2Fxenial

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.2.6p5-1

1.2.6p12-1

1.2.6p12-1ubuntu0.16.04.1

1.2.6p12-1ubuntu0.16.04.1+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "check-mk-agent",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        },
        {
            "binary_name": "check-mk-agent-logwatch",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        },
        {
            "binary_name": "check-mk-config-icinga",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        },
        {
            "binary_name": "check-mk-config-nagios3",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        },
        {
            "binary_name": "check-mk-livestatus",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        },
        {
            "binary_name": "check-mk-multisite",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        },
        {
            "binary_name": "check-mk-server",
            "binary_version": "1.2.6p12-1ubuntu0.16.04.1+esm1"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-8833.json"

Ubuntu:18.04:LTS / check-mk