CVE-2026-42845: getgrav grav-plugin-form External Control of File Name or Path
Vulnerability summary
CVE-2026-42845 is a high (CVSS 7.7) External Control of File Name or Path vulnerability in getgrav grav-plugin-form. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.3% of scored vulnerabilities.
Timeline
- 11-05-2026PublishedVulnerability first disclosed.
- 12-05-2026Last modifiedVulnerability information updated.
Description
The form plugin for Grav adds the ability to create and use forms. Prior to 9.1.0 , there is an unauthenticated page-content overwrite via file upload (GHSA-w4rc-p66m-x6qq). Public form uploads now strip path components from the POST-supplied filename and hard-block page-content extensions (`md`, `yaml`, `yml`, `json`, `twig`, `ini`) regardless of the configurable dangerous-extensions list. A permissive `accept` policy combined with the default `destination: self@` could otherwise let an attacker overwrite the page's own `.md` and pivot to super-admin via a `process: save` action. This vulnerability is fixed in 9.1.0.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST7.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS trend
Probability
0.45%
Chance of exploitation in the next 30 days
Percentile
37%
Versus all other CVEs
30-day change
-0.18 pp
From 0.62% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Getgrav1 product
- grav-plugin-form< 9.1.0
1 vendor · 1 product
References
2 links- github.com/getgrav/grav/security/advisories/GHSA-w4rc-p66m-x6qqX Refsource CONFIRM