What’s Vulnerable › Vulnerabilities

CVE-2026-29052: HumHub Calendar Module: Stored XSS in Event Types

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-05 · updated 2026-09-02
• Weakness: CWE-79

Description

The Calendar module for HumHub enables users to create one-time or recurring events, manage attendee invitations, and efficiently track all scheduled activities. Prior to version 1.8.11, a Stored Cross-Site Scripting (XSS) vulnerability in the Event Types of the HumHub Calendar module impacts users viewing events created by an administrative account. This issue has been patched in version 1.8.11.

Affected products

• humhub calendar: before 1.8.11 — fixed in 1.8.11

How to fix

Upgrade to a fixed version: humhub calendar 1.8.11. Check the vendor advisory for mitigations.

References

• https://github.com/humhub/calendar/releases/tag/v1.8.11
• https://github.com/humhub/calendar/security/advisories/GHSA-gqj3-pmp2-mrx8

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