CVE-2026-54003

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 58% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
—
EPSS
42.4%
KEV
Not listed

Published

June 18, 2026

Last Modified

July 10, 2026

Advisory Details (8)

Auto-updated Jul 9, 2026
Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available

External Initialization of the Panel on reverse proxy setups with the `Forwarded`, `X-Client-IP` or `X-Real-IP` header · Advisory · getkirby/kirby · GitHub

https://github.com/getkirby/kirby/security/advisories/GHSA-whxw-24jc-cwmv
github_release Patch Available

5.4.4

Patch available: getkirby/kirby 5.4.4

https://github.com/getkirby/kirby/releases/tag/5.4.4
github_release Patch Available

4.9.4

Patch available: getkirby/kirby 4.9.4

https://github.com/getkirby/kirby/releases/tag/4.9.4
github_pr Patch Available

fix: read Forwarded `for=` field from parsed fields, not host parts

Patch available: getkirby/kirby 5.4.4 (PR #8166 merged 2026-05-28)

https://github.com/getkirby/kirby/pull/8166
github_commit Patch Available

commit ab992dc14961 (getkirby/kirby)

Patch available: getkirby/kirby 5.4.4 (contains commit ab992dc14961)

https://github.com/getkirby/kirby/commit/ab992dc149610b90e337c2955ab6ccb7f72ffb3a
github_commit Patch Available

commit 66a3a14bf089 (getkirby/kirby)

Patch available: getkirby/kirby 5.4.4 (contains commit 66a3a14bf089)

https://github.com/getkirby/kirby/commit/66a3a14bf0892d320723ba766cd5f1d33a51d15b
github_commit Patch Available

commit 3423f66c01db (getkirby/kirby)

Patch available: getkirby/kirby 4.9.4 (contains commit 3423f66c01db)

https://github.com/getkirby/kirby/commit/3423f66c01dbc0455862e23ee699d2aa469f3234
github_commit Patch Available

commit 1c7fee90e491 (getkirby/kirby)

Patch available: getkirby/kirby 4.9.4 (contains commit 1c7fee90e491)

https://github.com/getkirby/kirby/commit/1c7fee90e49153cf9ca4a6ec17481d25fbedc48d

Vendor Advisories for CVE-2026-54003(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
getkirby/cms5.0.0 ... 5.4.3 (41 versions)5.4.4—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 02:00 UTCEPSS rescore
  12. 2026-07-15 02:00 UTCEPSS rescore
  13. 2026-07-13 22:31 UTCEPSS rescore
  14. 2026-07-13 06:13 UTCEPSS rescore
  15. 2026-07-13 06:13 UTCEPSS rescore
  16. 2026-07-12 05:46 UTCEPSS rescore
  17. 2026-07-11 08:27 UTCEPSS rescore
  18. 2026-07-11 08:27 UTCEPSS rescore
  19. 2026-07-09 19:13 UTCEG score recompute▲ 9.10
  20. 2026-07-09 19:12 UTCMITRE cvelistV5CVSS v3 → 9.1 · CVSS v4 → 9.1
  21. 2026-06-18 15:08 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54003?
CVE-2026-54003 is a critical vulnerability published on June 18, 2026. 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…
When was CVE-2026-54003 disclosed?
CVE-2026-54003 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54003 actively exploited?
CVE-2026-54003 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 42.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54003?
CVE-2026-54003 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-54003?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54003, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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