What is CVE-2026-29052?

CVE-2026-29052 is a medium-severity vulnerability in Humhub Calendar, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-05.

How severe is CVE-2026-29052?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Humhub Calendar

CVE-2026-29052

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (5.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Humhub Calendar — versions < 1.8.11

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
security-advisories@github.com (Product, x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-29052?: CVE-2026-29052 is a medium-severity vulnerability in Humhub Calendar, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-03-05.
How severe is CVE-2026-29052?: Medium severity. CVSS v3 base score is 6.1 out of 10.