CVE-2026-61457

HIGH

Grav before 1.0.3 Remote Code Execution via File Upload Extension Bypass

Title source: cna
STIX 2.1

Description

The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 contains a file upload extension bypass in the API media controller. HandlesMediaUploads::validateFileExtension() inspects only the final file extension via pathinfo($filename, PATHINFO_EXTENSION), so a user with api.media.write permission can upload a file with a double extension such as shell.php.jpg to bypass the dangerous extensions blocklist. The web server may then execute the file as PHP, resulting in remote code execution.

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-66v2-vxxf-xc3v)
https://github.com/getgrav/grav/security/advisories/GHSA-66v2-vxxf-xc3v
Third Party Advisory third-party-advisory
VulnCheck Advisory: Grav before 1.0.3 Remote Code Execution via File Upload Extension Bypass
https://www.vulncheck.com/advisories/grav-before-remote-code-execution-via-file-upload-extension-bypass

Scores

CVSS v3 8.8
EPSS 0.0046
EPSS Percentile 37.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-434
Status published
Products (2)
getgrav/grav < 1.0.3
getgrav/grav 1.0.3
Published Jul 15, 2026
Tracked Since Jul 15, 2026