CVE-2026-29052: The Calendar module for HumHub enables users to create one-time or recurring events, manage attendee invitatio

Q: How do I fix CVE-2026-29052?

calendar: upgrade to 1.8.11. Exact commands for each OS are on this page.

Q: Is CVE-2026-29052 being exploited?

CVE-2026-29052 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-29052 affect?

CVE-2026-29052 affects calendar. Severity is medium (CVSS 6.1). 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

Q: How urgent is CVE-2026-29052?

Priority 23/100. No elevated risk signals yet.

Routine

MEDIUM 6.1UPGRADE

CVE-2026-29052 is a medium-severity flaw (CVSS 6.1) affecting calendar. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 94%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-03-05
Last modified	2026-09-02

Publisher (CNA): GitHub, Inc. · Vendor: humhub

Last updated 2026-09-02 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-05 06:16 UTCPublished CVE record published
2026-09-02 14:35 UTCUpdated Record last modified

humhub calendar UPGRADE

Affected: < 1.8.11

Fixed in: 1.8.11

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy calendar || rpm -q calendar || calendar --version

2. UPGRADE to 1.8.11 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade calendar

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade calendar

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-29052?

calendar: upgrade to 1.8.11. Exact commands for each OS are on this page.

Is CVE-2026-29052 being exploited?

CVE-2026-29052 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-29052 affect?

CVE-2026-29052 affects calendar. Severity is medium (CVSS 6.1). 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

How urgent is CVE-2026-29052?

Priority 23/100. No elevated risk signals yet.

Related CVEs

CVE-2025-66511 MEDIUM 4.8 UPGRADE Nextcloud Calendar is a calendar app for Nextcloud
CVE-2025-66550 MEDIUM 5.7 UPGRADE Nextcloud Calendar is a calendar app for Nextcloud
CVE-2025-66546 LOW 3.3 UPGRADE Nextcloud Calendar is a calendar app for Nextcloud
CVE-2026-45286 MEDIUM 4.3 UPGRADE Nextcloud is an open source content collaboration platform
CVE-2025-21035 MEDIUM 4.6 UPGRADE Improper access control in Samsung Calendar prior to version 12.5.06.5 in Android 14 and 12.6.01.12 in Android

References

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