dbcve.org
KirbyApplication · Getkirby

CVE-2026-32870

HIGH · 7.5 CVSS v3.1 Published 2026-04-24
Fix available
A fix is available. Upgrade to 4.9.0 / 5.4.0 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
KirbyApplication
Affected:< 4.9.0>= 5.0.0, < 5.4.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.9.0 / 5.4.0 or later
Fixed in 4.9.05.4.0
Vendor patch github.com →
Recommended fix High confidence

Kirby 4.9.0 (for 4.x users) or Kirby 5.4.0 (for 5.x users)

  1. Identify the current Kirby major version in use (4.x or 5.x) by checking the composer.json or kirby version
  2. If using Kirby 4.x: Upgrade to Kirby 4.9.0 or later by running: composer require getkirby/kirby:^4.9.0
  3. If using Kirby 5.x: Upgrade to Kirby 5.4.0 or later by running: composer require getkirby/kirby:^5.4.0
  4. After upgrading, test any custom code that uses Xml::value(), Xml::tag(), Xml::create(), or Data::encode($string, 'xml') to ensure XML generation still works correctly
  5. Verify the upgrade by confirming the Xml::value() method now properly validates that the entire string consists only of valid CDATA blocks with no additional structured data
Caveat Review custom code that uses XML generation methods (Xml::value, Xml::tag, Xml::create, Data::encode with 'xml') as the behavior change may affect existing implementations that relied on the previous CDATA handling

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-32870 in production — separate from our analysis above.

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