CVE-2026-29052
Received Received - Intake
Stored XSS in HumHub Calendar Module Allows Admin Event Exploitation

Publication date: 2026-03-05

Last updated on: 2026-03-09

Assigner: GitHub, Inc.

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.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-03-05
Last Modified
2026-03-09
Generated
2026-06-16
AI Q&A
2026-03-05
EPSS Evaluated
2026-06-15
NVD
CVE-2026-29052
EUVD
EUVD-2026-9787
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
humhub calendar to 1.8.11 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-79 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.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

CVE-2026-29052 is a Stored Cross-Site Scripting (XSS) vulnerability in the Event Types feature of the HumHub Calendar module. This vulnerability allows malicious scripts to be stored within event types and executed when users view events created by an administrative account.

It affects versions of the HumHub Calendar module prior to 1.8.11 and has been fixed in version 1.8.11 by improving the HTML encoding of event types.

Impact Analysis

This vulnerability can impact you by allowing attackers to execute malicious scripts in the context of users viewing calendar events created by an administrative account.

Such script execution can lead to compromise of user security, including potential theft of session tokens, unauthorized actions performed on behalf of users, or other malicious activities.

Users are advised to upgrade to version 1.8.11 or later to mitigate this risk. If upgrading immediately is not possible, restricting permissions for creating and managing Event Types to highly trusted administrators is recommended.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate the vulnerability CVE-2026-29052, the primary recommended step is to upgrade the HumHub Calendar module to version 1.8.11 or later, where the issue has been patched.

If immediate upgrading is not possible, restrict the permissions for creating and managing Event Types to only highly trusted administrators to reduce the risk of exploitation.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-29052. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart