CVE-2026-42845

Grav: Anonymous Page Content Overwrite via Form File Upload filename Override

HIGH
7.7
CVSS Score
Published: May 11, 2026 at 03:44 PM UTC
Updated: October 26, 2026 at 06:10 PM UTC
1 product affected across 1 vendorGrav Plugin Form

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Severity
HIGH7.7
Exploit prediction
EPSS 0.7%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 9.1.0
Affected range stops below 9.1.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-73

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