CVE-2026-27613CWE-78CWE-88

CGI Parameter Injection (Bypass of STRICT_CGI_PARAMS and EscapeShellParam)

Critical · published February 25, 2026

CVSS v4.0
10.0
EPSS
1%
Percentile
72.3
In the wild
Unconfirmed
What it is

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`).

The record
Technical detail
CVSS v4.0
10.0 · CRITICAL
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
EPSS
0.01403 · 72.3th percentile
Weaknesses
CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'); CWE-88 · Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Published
2026-02-25T22:58Z
EPSS history
Timeline
  • 25 FEB 22:58Z
    CGI Parameter Injection (Bypass of STRICT_CGI_PARAMS and EscapeShellParam)
    cvelistv5