Vulnerability details

CVE-2026-34587

getkirby kirby

Kirby has Server-Side Template Injection (SSTI) via double template resolution in option rendering

CVSS 4.0
7.6High

Official description

Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, Kirby's user permissions control which user role is allowed to perform specific actions to content models in the CMS. These permissions are defined for each role in the user blueprint (`site/blueprints/users/...`). It is also possible to customize the permissions for each target model in the model blueprints (such as in `site/blueprints/pages/...`) using the `options` feature. The permissions and options together control the authorization of user actions. For pages, Kirby provides the `pages.create` and `pages.changeStatus` permissions (among others). In affected releases, Kirby checked these permissions independently and only for the respective action. However the `changeStatus` permission didn't take effect on page creation. New pages are created as drafts by default and need to be published by changing the page status of an existing page draft. This is ensured when the page is created via the Kirby Panel. However the REST API allows to override the `isDraft` flag when creating a new page. This allowed authenticated attackers with the `pages.create` permission to immediately create published pages, bypassing the normal editorial workflow. The problem has been patched in Kirby 4.9.0 and Kirby 5.4.0. Kirby has updated the `Options` logic to no longer double-resolve queries in option values coming from `OptionsQuery` or `OptionsApi` sources. Kirby now only resolves queries that are directly configured in the blueprints.

CVSS scores

ScoreVersionSourceVector
7.6High 4.0 CVEProject cvelistV5 (CNA) (GitHub_M) CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Affected products

VendorProductVersionsSource
getkirby kirby < 4.9.0 CVEProject cvelistV5 (CNA)
getkirby kirby >= 5.0.0, < 5.4.0 CVEProject cvelistV5 (CNA)

References and advisories

3
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Details

Published
2026-04-24
Last updated
2026-04-24
State
Published
Assigner (CNA)
GitHub_M

Exploit prediction (EPSS)

0.33%
Probability of exploitation in 30 days
26.9%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
None
Technical impact
Total

Weaknesses (CWE)

  • CWE-1336
    Improper Neutralization of Special Elements Used in a Template Engine