How severe is GHSA-63h4-w25c-3qv4?

GHSA-63h4-w25c-3qv4 has a CVSS score of 4.6/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-63h4-w25c-3qv4?

GHSA-63h4-w25c-3qv4 affects the following packages: getkirby/cms (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-63h4-w25c-3qv4?

Update getkirby/cms to 4.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-63h4-w25c-3qv4 is resolved across your whole dependency graph.

How do I detect GHSA-63h4-w25c-3qv4 in my Packagist dependencies?

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.

How do I mitigate GHSA-63h4-w25c-3qv4 if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-63h4-w25c-3qv4?

O3 pinpoints whether GHSA-63h4-w25c-3qv4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-63h4-w25c-3qv4 actively exploited in the wild?

No public exploit code has been indexed for GHSA-63h4-w25c-3qv4 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-63h4-w25c-3qv4?

GHSA-63h4-w25c-3qv4 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 27th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-63h4-w25c-3qv4?

GHSA-63h4-w25c-3qv4 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-63h4-w25c-3qv4 published, and has it been updated?

GHSA-63h4-w25c-3qv4 was published on February 26, 2024 and was last updated on February 26, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

GHSA-63h4-w25c-3qv4

MEDIUM

Kirby vulnerable to Cross-site scripting (XSS) in the link field "Custom" type

Also known asCVE-2024-27087

Published

Feb 26, 2024

Updated

Feb 26, 2024

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk27th percentile-0.43%

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

1 pkg affected

🐘getkirby/cms

Real-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 Kirby sites that use the new link field and output the entered link without additional validation or sanitization.

The attack commonly requires user interaction by another user or visitor.

The link dialog of the writer field is not affected as the writer field content is automatically sanitized by the Kirby backend code. You are also already protected if you limit the acceptable link types with the options field property.

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 new link field introduced in Kirby 4 allows several different link types that each validate the entered link to the relevant URL format. It also includes a "Custom" link type for advanced use cases that don't fit any of the pre-defined link formats.

As the "Custom" link type is meant to be flexible, it also allows the javascript: URL scheme. In some use cases this can be intended, but it can also be misused by attackers to execute arbitrary JavaScript code when a user or visitor clicks on a link that is generated from the contents of the link field.

Patches

The problem has been patched in Kirby 4.1.1. Please update to this or a later version to fix the vulnerability.

In the patch release, we have updated the link field to hide the "Custom" link type by default and added a warning to our documentation that this link type should only be enabled if additional validation is performed or no protection against XSS attacks is needed.

Credits

Thanks to Natwara Archeepsamooth (@PlyNatwara) for responsibly informing us about the javascript: attack vector.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`getkirby/cms`	≥ 4.0.0&&< 4.1.1	4.1.1

Detection & mitigation playbook

Open-source dependency

Detect
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 4.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-63h4-w25c-3qv4 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-63h4-w25c-3qv4 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-63h4-w25c-3qv4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### TL;DR This vulnerability affects Kirby sites that use the new [link field](https://getkirby.com/docs/reference/panel/fields/link) and output the entered link without additional validation or sanitization. The attack commonly requires user interaction by another user or visitor. The link dialog of the writer field is *not* affected as the writer field content is automatically sanitized by the Kirby backend code. You are also already protected if you limit the acceptable link types with the `options` field property. ---- ### Introduction Cross-site scripting (XSS) is a type of vulnerab

O3 Security · Impact-Aware SCA

Is GHSA-63h4-w25c-3qv4 in your dependencies?

O3 detects GHSA-63h4-w25c-3qv4 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works