Vulnerability Description
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`).
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ritlabs | Tinyweb | < 2.01 |
Related Weaknesses (CWE)
References
- https://github.com/maximmasiutin/TinyWeb/commit/d9dbda8db49da69d2160e1c527e782b7Patch
- https://github.com/maximmasiutin/TinyWeb/releases/tag/v2.01Release Notes
- https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-rfx5-fh9m-9jj9Vendor Advisory
- https://www.masiutin.net/tinyweb-cve-2026-27613.htmlThird Party Advisory
FAQ
What is CVE-2026-27613?
CVE-2026-27613 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 c...
How severe is CVE-2026-27613?
CVE-2026-27613 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-27613?
Check the references section above for vendor advisories and patch information. Affected products include: Ritlabs Tinyweb.