Summary
Due to a broken access control vulnerability in the /admin/pages/{page_name} endpoint, an editor ( user with full permissions to pages ) can change the functionality of a form after submission.
Details
Due to improper authorization checks when modifying critical fields on a POST request to /admin/pages/{page_name}, an editor with only permissions to change basic content on the form is now able to change the functioning of the form through modifying the content of the data[_json][header][form] which is the YAML frontmatter which includes the process section which dictates what happens after a user submits the form which include some important actions that could lead to further vulnerabilities.
PoC
Have Admin and Form plugins installed
Connect to panel as admin, create user and give him permission for pages all
Now connect as that user and notice you cant edit any process field in the panel
Change anything in the content of the form and save
Intercept the request:
Now modify the field `data[_json][header][form] with the following payload URL-encoded not like this:
{"name":"ssti-test 2","fields":{"name":{"type":"text","label":"Name","required":true}},"buttons":{"submit":{"type":"submit","value":"Submit"}},"process":[{"message":"{{ evaluate_twig(form.value('name')) }}"}]}
- Change the field and forward it:
Request goes through and changes have been made to the form.
Fix recommendation
- Implement proper authorization checks to such requests especially when it contains fields user shouldn't be able to modify based on his role.
Impact
- Attacker can modify submission logic of the form which leads to changing redirect value, email sending, changing template, breaking out of the Twig sandbox potentially executing code...
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-66301? CVE-2025-66301 is a high-severity security vulnerability in getgrav/grav (composer), affecting versions < 1.8.0-beta.27. It is fixed in 1.8.0-beta.27.
- Which versions of getgrav/grav are affected by CVE-2025-66301? getgrav/grav (composer) versions < 1.8.0-beta.27 is affected.
- Is there a fix for CVE-2025-66301? Yes. CVE-2025-66301 is fixed in 1.8.0-beta.27. Upgrade to this version or later.
- Is CVE-2025-66301 exploitable, and should I be worried? Whether CVE-2025-66301 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-66301 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-66301? Upgrade
getgrav/gravto 1.8.0-beta.27 or later.