What is the CVSS score of CVE-2026-29052?

CVE-2026-29052 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Calendar are affected by CVE-2026-29052?

Organizations using Calendar should be aware of moderate risk from CVE-2026-29052, a cross-site scripting vulnerability rated CVSS 6.1.

How to fix or mitigate CVE-2026-29052?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Calendar CVE-2026-29052

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-03-05 security-advisories@github.com

XSS Calendar

6.1

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 05, 2026 - 06:16 nvd

MEDIUM 6.1

DescriptionGitHub Advisory

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.

AnalysisAI

HumHub Calendar module versions prior to 1.8.11 contain a stored XSS vulnerability in Event Types that allows attackers to inject malicious scripts viewed by users accessing events created by administrative accounts. An attacker with event creation privileges can execute arbitrary JavaScript in the browsers of users viewing affected events, potentially compromising session tokens or sensitive information. No patch is currently available for affected installations.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Calendar. 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.

RemediationAI

Fixed in version 1.8.11.. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.