CVE-2026-27613CRITICAL 9.8EPSS p50.1%

CVE-2026-27613CVE-2026-27613

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`).

Scoring

CVSS 3.19.8 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS0.75% probability of exploitation · percentile 50.1% · 2026-06-18T12:00:27Z
Published2026-02-25
Last modified2026-03-04

Underlying weaknesses· 2

CWE-78CWE-88

References

  1. https://github.com/maximmasiutin/TinyWeb/commit/d9dbda8db49da69d2160e1c527e782b73b5ffb6b
  2. https://github.com/maximmasiutin/TinyWeb/releases/tag/v2.01
  3. https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-rfx5-fh9m-9jj9
  4. https://www.masiutin.net/tinyweb-cve-2026-27613.html

2

TypeTargetConfidenceTier
WeaknessImproper Neutralization of Special Elements used in an OS Command ('OS Command Injection')cwe-780%live
WeaknessImproper Neutralization of Argument Delimiters in a Command ('Argument Injection')cwe-880%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CVE
CVE-2026-22781
CVE
CVE-2026-28497
CVE
CVE-2026-29046
CVE
CVE-2025-3267
CVE
PHP-CGI Query String Parameter Vulnerability
CVE
PHP-CGI OS Command Injection Vulnerability
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.