CVE-2026-54003: Kirby is an open-source content management system

This month

CRITICAL 9.1REMOTE

CVE-2026-54003 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Kirby is an open-source content management system. Prior to 4.9.4 and from 5.4.4, Kirby sites with no configured user accounts that run on publicly accessible servers behind a reverse proxy setting the Forwarded, X-Client-IP, or X-Real-IP request header could allow remote attackers to install the Panel and create the first admin user because local-IP checks trusted those headers incorrectly. This issue is fixed in versions 4.9.4 and 5.4.4.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Weakness	CWE-454
Published	2026-07-09
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-07-09 19:17 UTCPublished CVE record published
2026-10-25 17:10 UTCUpdated Record last modified

Exact fixes by distribution

Composer (PHP) · getkirby/cms · FIXED · 4.9.4 · vulnerable: <= 4.9.3 · source

composer require "getkirby/cms:>=4.9.4"

Fedora 46 · log4cplus · FIXED · 2.2.0.1-2.fc46 · FEDORA-2026-fc241370c9 · source

sudo dnf upgrade --advisory=FEDORA-2026-fc241370c9

Fedora ELN · velocitty · FIXED · 1.0.3-2.eln159 · FEDORA-2026-edae8cd295 · source

sudo dnf upgrade --advisory=FEDORA-2026-edae8cd295

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-54003?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-54003 being exploited?

CVE-2026-54003 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-54003 affect?

CVE-2026-54003 affects affected software. Severity is critical (CVSS 9.1). Kirby is an open-source content management system. Prior to 4.9.4 and from 5.4.4, Kirby sites with no configured user accounts that run on publicly accessible servers behind a reverse proxy setting the Forwarded, X-Client-IP, or X-Real-IP r

How urgent is CVE-2026-54003?

Priority 50/100. Critical severity; Remotely exploitable, no login, no user action

References

← Back to latest CVEs