Authenticated site compromise via double option resolution
Published Apr 24, 2026 · Updated Apr 24, 2026
Server-side template injection in Kirby before 4.9.0 and 5.0.0 through 5.3.3 allows remote authenticated users to read or alter site data. The Options logic sends query- or API-derived option values through the query parser a second time, executing embedded expressions instead of treating them as literal data. Exposure requires dynamic options backed by untrusted data; an authenticated Panel user can trigger the expression, or a higher-privileged user must load the manipulated view.
Summary
What happened
Server-side template injection in Kirby before 4.9.0 and 5.0.0 through 5.3.3 allows remote authenticated users to read or alter site data. The Options logic sends query- or API-derived option values through the query parser a second time, executing embedded expressions instead of treating them as literal data. Exposure requires dynamic options backed by untrusted data; an authenticated Panel user can trigger the expression, or a higher-privileged user must load the manipulated view.
The record
- CVE
- CVE-2026-34587
- Published
- Apr 24, 2026
- Updated
- Apr 24, 2026
- Vendor
- Content Folder
- Product
- Kirby
- Classifications
- CWE-1336, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 24, 2026CVE publishedPublication date reported by the CVE source.
- Apr 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.9.0
- Affected versionversion=>= 5.0.0, < 5.4.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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