Arbitrary file write via post-render validation gap
Published Jul 15, 2026 · Updated Jul 15, 2026
Path traversal in the Form plugin for Grav before 9.1.8 allows remote authenticated users to write arbitrary files via crafted form data. The save handler validates process.save.filename before Twig renders it with submitted values, then joins the unchecked result to the destination path. A user with api.pages.write must first configure a Twig-templated filename; a later form submission can escape the data directory and place PHP in a web-accessible location.
Summary
What happened
Path traversal in the Form plugin for Grav before 9.1.8 allows remote authenticated users to write arbitrary files via crafted form data. The save handler validates process.save.filename before Twig renders it with submitted values, then joins the unchecked result to the destination path. A user with api.pages.write must first configure a Twig-templated filename; a later form submission can escape the data directory and place PHP in a web-accessible location.
The record
- CVE
- CVE-2026-61873
- Published
- Jul 15, 2026
- Updated
- Jul 15, 2026
- Vendor
- Grav
- Product
- Grav
- Classifications
- CWE-73, T1505.003
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 15, 2026CVE publishedPublication date reported by the CVE source.
- Jul 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <9.1.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Twig-processed filename path traversal proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo