---
id: CVE-2026-45368
title: Kirby is an open-source content management system
summary: >-
  Kirby is an open-source content management system. In versions prior to 4.9.1
  and 5.4.1, the underlying URL methods for the KirbyTags and image blocks
  components did not filter out malicious URL values that resolve to script
  execution. T…
severity: none
cwe:
  - CWE-79
published: '2026-07-16'
updated: '2026-07-18'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45368'
references:
  - url: 'https://github.com/getkirby/kirby/releases/tag/5.4.1'
    label: security-advisories@github.com
  - url: 'https://github.com/getkirby/kirby/security/advisories/GHSA-qvjf-922g-pj44'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00534
epssPercentile: 0.42616
ingestedAt: '2026-07-18T20:24:54.730Z'
---

## Overview

Kirby is an open-source content management system. In versions prior to 4.9.1 and 5.4.1, the underlying URL methods for the KirbyTags and image blocks components did not filter out malicious URL values that resolve to script execution. The vulnerability affects four first-party Kirby renderers that produce `<a href="…">` output from editor-supplied field values: the (`link: …)` KirbyTag, the `link`: parameter of the `(image: …)` KirbyTag when it does not resolve to a known file or `self`, the `link` field of the built-in image block, and the HTML importer for the `blocks` field (which accepted the same malicious input as the image block `link` field). While simple `avascript:` URLs were already deactivated by treating them as a relative path and prepending a single slash to the URL, the use of URLs of the format `javascript://x%0A…` bypasses this protection. The `vbscript:`, `data:`, `livescript:`, `mocha:` and `jar:` schemes are affected by the same underlying gap. This issue has been fixed in versions 4.9.1 and 5.4.1.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.