GHSA-v8x2-fjv7-8hjh
GHSA-v8x2-fjv7-8hjh is a CWE-285 vulnerability in getgrav/grav. O3 Security confirms whether GHSA-v8x2-fjv7-8hjh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Grav has Broken Access Control which allows an Editor to modify the page's YAML Frontmatter to alter form processing actions
Real-World Exposure
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Description
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
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Have Admin and Form plugins installed
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Connect to panel as admin, create user and give him permission for pages all
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Now connect as that user and notice you cant edit any process field in the panel
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Change anything in the content of the form and save
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Intercept the request:
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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.
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...
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getgrav/grav | all versions | 1.8.0-beta.27 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getgrav/grav. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update getgrav/grav to 1.8.0-beta.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-v8x2-fjv7-8hjh is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-v8x2-fjv7-8hjh is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-v8x2-fjv7-8hjh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-v8x2-fjv7-8hjh in your dependencies?
O3 detects GHSA-v8x2-fjv7-8hjh across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.