Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.46% for the current model date.
BlackTreeCVE Intelligencegetkirby · kirby
Official source article: GitHub GHSA-9WFJ-C55W-J9QR ↗. Check the applicable product and release in the original source.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| composergetkirby/cms | < 4.9.0 | 4.9.0 | GitHub advisory ↗upstream repository advisory · 27 Apr 2026 |
| composergetkirby/cms | >= 5.0.0, < 5.4.0 | 5.4.0 | GitHub advisory ↗upstream repository advisory · 27 Apr 2026 |
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch availableKirby is an open-source content management system. Kirby's `Xml::value()` method has special handling for `<![CDATA[ ]]>` blocks. If the input value is already valid `CDATA`, it is not escaped a second time but allowed to pass through. However, prior to versions 4.9.0 and 5.4.0, it was possible to trick this check into allowing values that only contained a valid `CDATA` block but also contained other structured data outside of the `CDATA` block. This structured data would then also be allowed to pass through, circumventing the value protection. The `Xml::value()` method is used in `Xml::tag()`, `Xml::create()` and in the `Xml` data handler (e.g. `Data::encode($string, 'xml')`). Both the vulnerable methods and the data handler are not used in the Kirby core. However they may be used in site or plugin code, e.g. to create XML strings from input data. If those generated files are passed to another implementation that assigns specific meaning to the XML schema, manipulation of this system's behavior is possible. Kirby sites that don't use XML generation in site or plugin code are not affected. The problem has been patched in Kirby 4.9.0 and Kirby 5.4.0. In all of the mentioned releases, Kirby has added additional checks that only allow unchanged `CDATA` passthrough if the entire string is made up of valid `CDATA` blocks and no structured data. This protects all uses of the method against the described vulnerability.
Kirby is an open-source content management system. Kirby's `Xml::value()` method has special handling for `<![CDATA[ ]]>` blocks. If the input value is already valid `CDATA`, it is not escaped a second time but allowed to pass through. However, prior to versions 4.9.0 and 5.4.0, it was possible to trick this check into allowing values that only contained a valid `CDATA` block but also contained other structured data outside of the `CDATA` block. This structured data would then also be allowed to pass through, circumventing the value protection. The `Xml::value()` method is used in `Xml::tag()`, `Xml::create()` and in the `Xml` data handler (e.g. `Data::encode($string, 'xml')`). Both the vulnerable methods and the data handler are not used in the Kirby core. However they may be used in site or plugin code, e.g. to create XML strings from input data. If those generated files are passed to another implementation that assigns specific meaning to the XML schema, manipulation of this system's behavior is possible. Kirby sites that don't use XML generation in site or plugin code are not affected. The problem has been patched in Kirby 4.9.0 and Kirby 5.4.0. In all of the mentioned releases, Kirby has added additional checks that only allow unchanged `CDATA` passthrough if the entire string is made up of valid `CDATA` blocks and no structured data. This protects all uses of the method against the described vulnerability.
The product does not properly neutralize special elements that are used in XML, allowing attackers to modify the syntax, content, or commands of the XML before it is processed by an end system.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
Kirby is an open-source content management system. Kirby's `Xml::value()` method has special handling for `<![CDATA[ ]]>` blocks. If the input value is already valid `CDATA`, it is not escaped a second time but allowed to pass through. However, prior to versions 4.9.0 and 5.4.0, it was possible to trick this check into allowing values that only contained a valid `CDATA` block but also contained other structured data outside of the `CDATA` block. This structured data would then also be allowed to pass through, circumventing the value protection. The `Xml::value()` method is used in `Xml::tag()`, `Xml::create()` and in the `Xml` data handler (e.g. `Data::encode($string, 'xml')`). Both the vulnerable methods and the data handler are not used in the Kirby core. However they may be used in site or plugin code, e.g. to create XML strings from input data. If those generated files are passed to another implementation that assigns specific meaning to the XML schema, manipulation of this system's behavior is possible. Kirby sites that don't use XML generation in site or plugin code are not affected. The problem has been patched in Kirby 4.9.0 and Kirby 5.4.0. In all of the mentioned releases, Kirby has added additional checks that only allow unchanged `CDATA` passthrough if the entire string is made up of valid `CDATA` blocks and no structured data. This protects all uses of the method against the described vulnerability.
The product does not properly neutralize special elements that are used in XML, allowing attackers to modify the syntax, content, or commands of the XML before it is processed by an end system.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-91: XML Injection (aka Blind XPath Injection). The product does not properly neutralize special elements that are used in XML, allowing attackers to modify the syntax, content, or commands of the XML before it is processed by an end system.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 24 Apr 2026 · Last source change 24 Apr 2026, 16:30 UTC · CWE-91 · XML Injection (aka Blind XPath Injection)
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.