CVE-2026-27613 CRITICAL

CVE-2026-27613: CGI Parameter Injection (Bypass of STRICT_CGI_PARAMS and EscapeShellParam)

Vendor Maximmasiutin
Product TinyWeb
Weakness CWE-78
Published February 25, 2026
Last update February 26, 2026

CVSS base score

10.0/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

What the vulnerability does

01Description

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. A vulnerability in versions prior to 2.01 allows unauthenticated remote attackers to bypass the web server's CGI parameter security controls. Depending on the server configuration and the specific CGI executable in use, the impact is either source code disclosure or remote code execution (RCE). Anyone hosting CGI scripts (particularly interpreted languages like PHP) using vulnerable versions of TinyWeb is impacted. The problem has been patched in version 2.01. If upgrading is not immediately possible, ensure `STRICT_CGI_PARAMS` is enabled (it is defined by default in `define.inc`) and/or do not use CGI executables that natively accept dangerous command-line flags (such as `php-cgi.exe`). If hosting PHP, consider placing the server behind a Web Application Firewall (WAF) that explicitly blocks URL query string parameters that begin with a hyphen (`-`) or contain encoded double quotes (`%22`).

Key dates

02Disclosure timeline

February 25, 2026 CVE published
February 26, 2026 Record updated