CVE-2026-61873 | Grav before 9.1.8 contains an arbitrary file write vulnerabi… | CVSS 8.1 HIGH

Description

Grav before 9.1.8 contains an arbitrary file write vulnerability in the Form plugin's process.save.filename parameter, which is validated against path traversal before Twig processing but never re-validated after rendering. Attackers can submit form data containing path traversal sequences that are processed through Twig templates, allowing them to write arbitrary files including PHP webshells to the web root or other sensitive directories.

Metadata

CVE ID: CVE-2026-61873
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-07-10 21:54 UTC
Published: 2026-07-15 11:25 UTC
Last updated: 2026-07-15 11:47 UTC
Primary CWE: CWE-73
External Control of File Name or Path
Vendor / Product: getgrav / grav
Sources: cve.org · NVD

Severity & Metrics

8.1 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Affected products (1)

Vendor	Product	Platform	Versions
getgrav	grav	—	0 < 9.1.8, 9.1.8

Weakness (CWE)

CWE	Source	Description
CWE-73	cna	External Control of File Name or Path

CVSS scores (2)

Score	Severity	Version	Source	Vector
8.1	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
7.2	HIGH	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

References (2)

GitHub Security Advisory (GHSA-q532-mvx7-42qg) https://github.com/getgrav/grav/security/advisories/GHSA-q532-mvx7-42qg
VulnCheck Advisory: Grav before 9.1.8 Arbitrary File Write via Twig-Processed Filename https://www.vulncheck.com/advisories/grav-before-arbitrary-file-write-via-twig-processed-filename