CVE-2026-27613
CGI Parameter Injection (Bypass of STRICT_CGI_PARAMS and EscapeShellParam)
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`).
INFO
Published Date :
Feb. 25, 2026, 11:16 p.m.
Last Modified :
March 4, 2026, 3:21 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Upgrade TinyWeb to version 2.01.
- Enable STRICT_CGI_PARAMS if upgrading is not possible.
- Avoid dangerous CGI executables like php-cgi.exe.
- Configure WAF to block malicious query strings.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-27613.
| URL | Resource |
|---|---|
| https://github.com/maximmasiutin/TinyWeb/commit/d9dbda8db49da69d2160e1c527e782b73b5ffb6b | Patch |
| https://github.com/maximmasiutin/TinyWeb/releases/tag/v2.01 | Release Notes |
| https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-rfx5-fh9m-9jj9 | Vendor Advisory |
| https://www.masiutin.net/tinyweb-cve-2026-27613.html | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-27613 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-27613
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27613 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27613 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 04, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:ritlabs:tinyweb:*:*:*:*:*:*:*:* versions up to (excluding) 2.01 Added Reference Type GitHub, Inc.: https://github.com/maximmasiutin/TinyWeb/commit/d9dbda8db49da69d2160e1c527e782b73b5ffb6b Types: Patch Added Reference Type GitHub, Inc.: https://github.com/maximmasiutin/TinyWeb/releases/tag/v2.01 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-rfx5-fh9m-9jj9 Types: Vendor Advisory Added Reference Type GitHub, Inc.: https://www.masiutin.net/tinyweb-cve-2026-27613.html Types: Third Party Advisory -
New CVE Received by [email protected]
Feb. 25, 2026
Action Type Old Value New Value Added 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`). Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-78 Added CWE CWE-88 Added Reference https://github.com/maximmasiutin/TinyWeb/commit/d9dbda8db49da69d2160e1c527e782b73b5ffb6b Added Reference https://github.com/maximmasiutin/TinyWeb/releases/tag/v2.01 Added Reference https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-rfx5-fh9m-9jj9 Added Reference https://www.masiutin.net/tinyweb-cve-2026-27613.html