How severe is CVE-2025-66298?

No CVSS score has been assigned to CVE-2025-66298 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-66298?

CVE-2025-66298 affects the following packages: getgrav/grav (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2025-66298?

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 CVE-2025-66298 is resolved across your whole dependency graph.

How do I detect CVE-2025-66298 in my Packagist dependencies?

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.

How do I mitigate CVE-2025-66298 if there is no patch (or I can't update yet)?

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.

Is CVE-2025-66298 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-66298 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-66298?

CVE-2025-66298 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 32th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-66298?

CVE-2025-66298 is classified as CWE-1336 (CWE-1336). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-66298 published, and has it been updated?

CVE-2025-66298 was published on December 1, 2025 and was last updated on November 11, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2025-66298 — grav

Fix: getgrav/grav@e372595

CVE-2025-66298 is a CWE-1336 vulnerability in getgrav/grav. A fix is available for getgrav/grav — see the affected versions and patch details below.

Grav is vulnerable to Server-Side Template Injection (SSTI) via Forms

Also known asGHSA-8535-hvm8-2hmv

Published

Dec 1, 2025

Updated

Nov 11, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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-2025-66298.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs32th percentile — riskier than 32% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐘getgrav/grav

Real-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

Having a simple form on site can reveal the whole Grav configuration details (including plugin configuration details) by using the correct POST payload. Sensitive information may be contained in the configuration details.

PoC

Create a simple form with two fields, 'registration-number' and 'hp'. Add a submit button and set the method to POST(screenshot attached below). Form name set to 'hero-form'. Send a POST request with the following payload and you will notice a response with a php array listing the whole Grav configuration details - including plugins(screenshot attached).

registration-number:d643aaaa

hp:vJyifp

form-name:hero-form

unique_form_id:{{var_dump(_context|slice(0,7))}}

Screenshot 2025-03-25 at 7 26 02 AM

Screenshot 2025-03-25 at 7 22 58 AM

Impact

Server-Side Template (SST) vulnerability. The vulnerability affects the latest Grav version as of 25th of Match 2025 (1.7.48) with all plugins installed (including forms plugin v.7.4.2) to their latest versions as well.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`getgrav/grav`	all versions	1.8.0-beta.27`composer require getgrav/grav:^1.8.0-beta.27`

Affected Products

1 product · 27 configurations

Application

gravgetgrav

< 1.8.0

1 version

1.8.0

Detection & mitigation playbook

Open-source dependency

Detect
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 1.8.0-beta.27 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-66298 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.

Frequently Asked Questions

### Summary Having a simple form on site can reveal the whole Grav configuration details (including plugin configuration details) by using the correct POST payload. Sensitive information may be contained in the configuration details. ### PoC Create a simple form with two fields, 'registration-number' and 'hp'. Add a submit button and set the method to POST(screenshot attached below). Form name set to 'hero-form'. Send a POST request with the following payload and you will notice a response with a php array listing the whole Grav configuration details - including plugins(screenshot attached).

O3 Security · Impact-Aware SCA

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