CVE-2025-66311 — getgrav/grav
Fix: getgrav/grav-plugin-admin@99f6532CVE-2025-66311 is a Cross-site Scripting (XSS) vulnerability in getgrav/grav. A fix is available for getgrav/grav — see the affected versions and patch details below.
Grav vulnerable to Cross-Site Scripting (XSS) Stored endpoint `/admin/pages/[page]` in Multiples parameters
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-66311.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
getgrav/gravReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/pages/[page] endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[header][metadata], data[header][taxonomy][category], and data[header][taxonomy][tag] parameters. These scripts are stored in the page frontmatter and executed automatically whenever the affected page is accessed or rendered in the administrative interface.
Details
Vulnerable Endpoint: POST /admin/pages/[page]
Parameters:
-
data[header][metadata] -
data[header][taxonomy][category] -
data[header][taxonomy][tag]
The application fails to properly sanitize user input when saving page metadata or taxonomy fields via the Admin Panel. As a result, an attacker with access to the admin interface can inject a malicious script using these parameters, and the script will be stored in the page's YAML frontmatter. When the page or metadata is rendered (especially in the Admin Panel), the payload is executed in the browser of any user with access.
PoC
Payload:
<script>alert('PoC-XXS51')</script>
Steps to Reproduce:
-
Log into the Grav Admin Panel and navigate to Pages.
-
Create or edit a page.
-
Inject the payload above into any of the following fields in the Options tab:
-
Metadata key name
-
Category under Taxonomy
-
Tag under Taxonomy
-
- Save the page.
When the page is loaded again in the Admin Panel or potentially on the frontend (depending on how the metadata is used), the script is executed, confirming the Stored XSS vulnerability.
Impact
Stored XSS vulnerabilities can result in serious consequences, including:
-
Session hijacking: Attackers can steal authentication cookies or tokens
-
Malware delivery: Injected scripts can download malicious software
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Credential theft: Fake input fields can capture usernames and passwords
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Sensitive data exposure: Access to internal metadata and browser data
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Administrative access compromise: Especially dangerous in admin-facing interfaces
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Phishing attacks: Users can be redirected to external malicious sites
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Reputation damage: Executing arbitrary scripts in trusted systems undermines credibility
by CVE-Hunters
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getgrav/grav | all versions | 1.11.0-beta.1composer require getgrav/grav:^1.11.0-beta.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getgrav/grav, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update getgrav/grav to 1.11.0-beta.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-66311 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-66311 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-66311. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-66311 in your dependencies?
O3 Security finds CVE-2025-66311 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.