grav: Improper Neutralization of Special Elements Used in a Template Engine
CVE-2025-66298 is a high-severity improper neutralization of special elements used in a template engine vulnerability in grav, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected grav versions: < 1.8.0-beta.27. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of grav you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
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.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.7 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
Grav is a file-based Web platform. Prior to 1.8.0-beta.27, having a simple form on site can reveal the whole Grav configuration details (including plugin configuration details) by using the correct POST payload to exploit a Server-Side Template (SST) vulnerability. Sensitive information may be contained in the configuration details. This vulnerability is fixed in 1.8.0-beta.27.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements Used in a Template Engine
The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine.
How developers prevent this class of flaw
- Choose a template engine that offers a sandbox or restricted mode, or at least limits the power of any available expressions, function calls, or commands.
- Use the template engine's sandbox or restricted mode, if available.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/getgrav/grav/security/advisories/GHSA-8535-hvm8-2hmvExploit, Third Party Advisory
Patches and release notes
Other vulnerabilities in grav
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Neutralization of Special Elements Used in a Template Engine vulnerabilities
- 8.8 High severity
- 8.3 High severity
- 7.2 High severity
- 8.8 High severity
- 10.0 Critical severity
- 7.2 High severity
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