GHSA-84hf-8gh5-575j
Kirby CMS has cross-site scripting (XSS) in the changes dialog
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
getkirby/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
TL;DR
This vulnerability affects all Kirby 5 sites that might have potential attackers in the group of authenticated Panel users or that allow external visitors to update page titles or usernames.
The attack requires user interaction by another Panel user and cannot be automated.
Introduction
Cross-site scripting (XSS) is a type of vulnerability that allows to execute any kind of JavaScript code inside the Panel session of the same or other users. In the Panel, a harmful script can for example trigger requests to Kirby's API with the permissions of the victim.
Such vulnerabilities are critical if you might have potential attackers in your group of authenticated Panel users. They can escalate their privileges if they get access to the Panel session of an admin user. Depending on your site, other JavaScript-powered attacks are possible.
Impact
The "Changes" dialog in the Panel displays all content models (pages, files, users) with changed content, i.e. with content that has not yet been published. Each changed model is listed with its preview image/icon and its title/name.
Attackers could change the title of any page or the name of any user to a malicious string. Then they could modify any content field of the same model without saving, making the model a candidate for display in the "Changes" dialog. If another authenticated user subsequently opened the dialog in their Panel, the malicious code would be executed.
Patches
The problem has been patched in Kirby 5.1.4. Please update to this or a later version to fix the vulnerability.
In the patch release, we have added the required escaping code to signal to the browser the intent of displaying plain text instead of code in the places where the model titles are rendered.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getkirby/cms | ≥ 5.0.0&&< 5.1.4 | 5.1.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getkirby/cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update getkirby/cms to 5.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-84hf-8gh5-575j is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-84hf-8gh5-575j is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-84hf-8gh5-575j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-84hf-8gh5-575j in your dependencies?
O3 detects GHSA-84hf-8gh5-575j across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.