How severe is CVE-2026-21896?

CVE-2026-21896 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-21896 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21896?

CVE-2026-21896 affects Getkirby Kirby. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21896?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-21896 have an EU (EUVD) identifier?

Yes. CVE-2026-21896 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1473.

When was CVE-2026-21896 published?

CVE-2026-21896 was published on 2026-01-08 and last updated on 2026-06-17.

CVE-2026-21896

CVE-2026-21896 is a medium-severity vulnerability in Getkirby Kirby with a CVSS 3.x base score of 5.7. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.7)
CVSS v4: 5.8
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-1473
Weakness: CWE-863
Affected product: Getkirby Kirby
Published: 2026-01-08
Last modified: 2026-06-17

Description

Kirby is an open-source content management system. From versions 5.0.0 to 5.2.1, Kirby is missing permission checks in the content changes API. This vulnerability affects all Kirby sites where user permissions are configured to prevent specific role(s) from performing write actions, specifically by disabling the update permission with the intent to prevent modifications to site content. This vulnerability does not affect those who have not altered the deviated from default user permissions. This issue has been patched in version 5.2.2.

Frequently asked questions

What is CVE-2026-21896?: Kirby is an open-source content management system. From versions 5.0.0 to 5.2.1, Kirby is missing permission checks in the content changes API. This vulnerability affects all Kirby sites where user permissions are configured to prevent specific role(s) from performing write actions, specifically by disabling the update permission with the intent to prevent modifications to site content. This vulnerability does not affect those who have not altered the deviated from default user permissions. This issue has been patched in version 5.2.2.
How severe is CVE-2026-21896?: CVE-2026-21896 has a CVSS 3.x base score of 5.7, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-21896 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21896?: CVE-2026-21896 affects Getkirby Kirby. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21896?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-21896 have an EU (EUVD) identifier?: Yes. CVE-2026-21896 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1473.
When was CVE-2026-21896 published?: CVE-2026-21896 was published on 2026-01-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:getkirby:kirby:*:*:*:*:*:*:*:*

More vulnerabilities in Getkirby Kirby

CVE-2025-31493 — Critical (CVSS 9.1): Kirby is an open-source content management system. A vulnerability in versions prior to 3.9.8.3, 3.10.1.2, and 4.7.1…
CVE-2025-30159 — Critical (CVSS 9.1): Kirby is an open-source content management system. A vulnerability in versions prior to 3.9.8.3, 3.10.1.2, and 4.7.1…
CVE-2026-41325 — High (CVSS 8.8): Kirby is an open-source content management system. Kirby's user permissions control which user role is allowed to…
CVE-2024-26483 — High (CVSS 8.8): An arbitrary file upload vulnerability in the Profile Image module of Kirby CMS v4.1.0 allows attackers to execute…
CVE-2026-34587 — High (CVSS 8.1): Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, Kirby's user permissions control…
CVE-2024-41964 — High (CVSS 8.1): Kirby is a CMS targeting designers and editors. Kirby allows to restrict the permissions of specific user roles. Users…

All CVEs affecting Getkirby Kirby →

Other CWE-863 (Incorrect Authorization) vulnerabilities

CVE-2026-48286 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9396 and earlier are affected by an Incorrect Authorization…
CVE-2026-48303 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) versions 7.4.3 build 9394 and earlier are affected by an Incorrect Authorization…
CVE-2026-44330 — Critical (CVSS 10.0): free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the…
CVE-2026-46595 — Critical (CVSS 10.0): Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of…
CVE-2026-33105 — Critical (CVSS 10.0): Improper authorization in Microsoft Azure Kubernetes Service allows an unauthorized attacker to elevate privileges over…
CVE-2026-32213 — Critical (CVSS 10.0): Improper authorization in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.

Browse all CWE-863 (Incorrect Authorization) vulnerabilities →