dbcve.org
CWE-83Weakness · CWE-83

CVE-2026-49276

HIGH · 7.4 CVSS v4.0 Published 2026-07-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
81/100
Remediation priority · High
Remotely reachable No privileges 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Kirby is an open-source content management system. Prior to 4.9.4 and 5.4.4, Kirby sites using the writer field in any blueprint allowed a scripting link to be included as the target of a link or email link in writer mark components, making the target clickable by the user who entered it and enabling self cross-site scripting in the Panel. This issue is fixed in versions 4.9.4 and 5.4.4.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Kirby CMS versions prior to 4.9.4 and 5.4.4 contain a stored cross-site scripting (XSS) vulnerability in the writer field component. Attackers can inject javascript: links as targets in writer mark components (links and email links), which become clickable in the Panel interface, enabling self-XSS attacks where the user who enters the malicious link can trigger execution.

MitigationUpgrade Kirby to version 4.9.4 or 5.4.4 or later to patch the vulnerability. If immediate patching is not possible, restrict access to the Panel and disable writer field usage in blueprints until the update can be applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
Authentication
X
User interaction
A
Scope
X

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Kirby CMS version
    Check the version file in your Kirby installation - typically in /kirby/composer.json or /site/composer.json under the 'version' or 'kirby/version' field, or access the Panel and check the bottom-left footer for the version number
    Affected if The installed version is prior to 4.9.4 or between 5.0.0 and 5.4.3 (prior to 5.4.4)
  2. Locate Kirby blueprints using writer fields
    Search your project's blueprints directory (typically /site/blueprints) for fields of type 'writer' - look for entries containing 'type: writer' in YAML files
    Affected if Any blueprints define writer fields, making the component active in the Panel
  3. Inspect content entries for javascript: links in writer fields
    Query your content database or examine content files (in /site/content) for any links containing 'javascript:' in their target attributes, particularly within writer field markups
    Affected if Any stored content contains javascript: links in writer field data, indicating active exploitation or malicious input
  4. Verify Panel access status
    Review your Kirby configuration (typically /site/config/config.php) for panel.session.timeout, panel.install, or authentication settings that determine who can access the Panel
    Affected if The Panel is accessible to users who can create or edit writer field content, as this is the attack surface

Your environment is affected if you are running Kirby CMS versions below 4.9.4 or below 5.4.4 and have writer fields enabled in any blueprints, regardless of whether malicious content is currently present.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Kirby to version 4.9.4 or 5.4.4 or later to patch the vulnerability. If immediate patching is not possible, restrict access to the Panel and disable writer field usage in blueprints until the update can be applied.

Recommended fix High confidence

Kirby 4.9.4 for 4.x line or Kirby 5.4.4 for 5.x line

  1. Identify the current Kirby version by checking the composer.json file or Kirby's version method
  2. If running Kirby 4.x, upgrade to version 4.9.4
  3. If running Kirby 5.x, upgrade to version 5.4.4
  4. Update the composer.json dependency (e.g., "getkirby/composer": "^4.9.4" or "^5.4.4")
  5. Run composer update to apply the changes
  6. Clear any cached Panel assets if applicable
  7. Verify the upgrade was successful by checking the Kirby version in the Panel

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49276 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data