CVE-2026-45334 Kirby: Content locks disclose IDs and emails of inaccessible users from `users.access/list` permissions
Low-privilege users can view email addresses and IDs of locked users, enabling account enumeration and phishing attacks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45334?
CVE-2026-45334 is a medium-severity vulnerability in getkirby kirby, published on 16 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Kirby is an open-source content management system. In versions prior to 4.9.1 and 5.4.1, the content-locking feature returned lock information without checking the requesting user's access permissions. Kirby's Panel includes a content-locking feature that records which user currently has a model open for editing. This lock prevents conflicting edits by multiple users and displays the locking user's identity in the Panel UI so other users know who to contact. Internally, the locking user's email address and identifier are included in every Panel view payload and in error responses returned when a user attempts to edit a model that is currently locked by another user. This allowed a low-privilege authenticated Panel user, whose role was configured with users.access: false or users.list: false, to learn the email address and identifier of any user who currently had a model open for editing in the Panel, including administrators and other higher-privilege users. Content locks are active for a configurable window (10 minutes by default). The email address can allow admin account enumeration, target phishing, and feed credential-stuffing attacks against the Kirby installation or other sites. The internal user ID can be cross-referenced with other endpoints once the requester has obtained a higher privilege through unrelated means. This issue has been fixed in versions 4.9.1 and 5.4.1.
Weakness: CWE-862
Which versions are affected by CVE-2026-45334?
4 open source packages ship an affected version, including getkirby/cms.
| Package | Affected | Fixed in |
|---|---|---|
getkirby/cms Packagist | All versions | 4.9.1 |
getkirby/cms Packagist | All versions | 4.9.1 |
getkirby/cms Packagist | From 5.0.0 | 5.4.1 |
getkirby/cms Packagist | From 5.0.0 | 5.4.1 |
How do I fix CVE-2026-45334?
Upgrade getkirby/cms to a fixed version for your release line: 4.9.1 or 5.4.1.
Is CVE-2026-45334 being exploited?
There is no known exploitation of CVE-2026-45334 in the wild and no public exploit code.
Sources
Also known as GHSA-39vq-49qm-r2mc.