CyberSecBulletin
CVE-2026-44174NVD status: Deferred

kirby: Use of Externally-Controlled Input to Select Classes or Code

Published Updated By the CyberSecBulletin desk

CVE-2026-44174 is a high-severity use of externally-controlled input to select classes or code vulnerability in kirby from Getkirby, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected kirby versions: < 4.9.1; >= 5.0.0, < 5.4.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of kirby you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Getkirbykirby< 4.9.1; >= 5.0.0, < 5.4.1Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (github.com).

Official description

Kirby is an open-source content management system. Prior to 4.9.1 and 5.4.1, Kirby did not validate the model attributes that were used in its collection queries, allowing attackers to include arbitrary model methods in their queries. This includes methods with sensitive data such as password() (disclosing the password hash) or root() (disclosing the absolute filesystem path on the server) as well as methods that perform impactful actions such as loginPasswordless() (causing a privilege escalation to another user) or delete() (deleting all queried models in one go if the authenticated user has appropriate permissions). This issue has been fixed in versions 4.9.1 and 5.4.1.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Externally-Controlled Input to Select Classes or Code

The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code.

How developers prevent this class of flaw

  • Refactor your code to avoid using reflection.
  • Do not use user-controlled inputs to select and load classes or code.
  • Apply strict input validation by using allowlists or indirect selection to ensure that the user is only selecting allowable classes or code.

More Use of Externally-Controlled Input to Select Classes or Code vulnerabilities (CWE-470)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in kirby

All kirby vulnerabilities

Recent Use of Externally-Controlled Input to Select Classes or Code vulnerabilities

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