CVE-2026-27613

9.8 CRITICAL
Published: February 25, 2026 Modified: March 04, 2026
View on NVD

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`).

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/maximmasiutin/TinyWeb/releases/tag/v2.01
Source: security-advisories@github.com
Release Notes
https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-rfx5-fh9m-9jj9
Source: security-advisories@github.com
Vendor Advisory
https://www.masiutin.net/tinyweb-cve-2026-27613.html
Source: security-advisories@github.com
Third Party Advisory

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.8 / 10.0
EPSS (Exploit Probability)
0.1%
33th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

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