CVE-2026-54003
CVE-2026-54003 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-454.
Key facts
- Severity: Critical (CVSS 4.0 base score 9.1)
- EPSS exploit prediction: 1% (44th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-454
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is CVE-2026-54003?
- 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.
- How severe is CVE-2026-54003?
- CVE-2026-54003 has a CVSS 4.0 base score of 9.1, rated critical severity.
- Is CVE-2026-54003 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-54003?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2026-54003 published?
- CVE-2026-54003 was published on 2026-07-09 and last updated on 2026-07-10.
References
- https://github.com/getkirby/kirby/commit/1c7fee90e49153cf9ca4a6ec17481d25fbedc48d
- https://github.com/getkirby/kirby/commit/3423f66c01dbc0455862e23ee699d2aa469f3234
- https://github.com/getkirby/kirby/commit/66a3a14bf0892d320723ba766cd5f1d33a51d15b
- https://github.com/getkirby/kirby/commit/ab992dc149610b90e337c2955ab6ccb7f72ffb3a
- https://github.com/getkirby/kirby/pull/8166
- https://github.com/getkirby/kirby/releases/tag/4.9.4
- https://github.com/getkirby/kirby/releases/tag/5.4.4
- https://github.com/getkirby/kirby/security/advisories/GHSA-whxw-24jc-cwmv
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