CVE-2026-27630 TinyWeb vulnerable to Remote Denial of Service via Thread/Connection Exhaustion (Slowloris)

High 8.7 Published 25 Feb 2026 Updated 26 Feb 2026

Exploited in the wild: Not known
Fix: None listed

What is CVE-2026-27630?

CVE-2026-27630 is a high-severity vulnerability in maximmasiutin TinyWeb, published on 25 Feb 2026.

Official description

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. Versions prior to version 2.02 are vulnerable to a Denial of Service (DoS) attack known as Slowloris. The server spawns a new OS thread for every incoming connection without enforcing a maximum concurrency limit or an appropriate request timeout. An unauthenticated remote attacker can exhaust server concurrency limits and memory by opening numerous connections and sending data exceptionally slowly (e.g. 1 byte every few minutes). Anyone hosting services using TinyWeb is impacted. Version 2.02 fixes the issue. The patch introduces a `CMaxConnections` limit (set to 512) and a `CConnectionTimeoutSecs` idle timeout (set to 30 seconds). As a temporary workaround if upgrading is not immediately possible, consider placing the server behind a robust reverse proxy or Web Application Firewall (WAF) such as nginx, HAProxy, or Cloudflare, configured to buffer incomplete requests and aggressively enforce connection limits and timeouts.

Weakness: CWE-770, CWE-400

Which versions are affected by CVE-2026-27630?

It affects 1 product.

Products include Ritlabs Tinyweb.

How do I fix CVE-2026-27630?

No fix has been published for CVE-2026-27630 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-27630 being exploited?

There is no known exploitation of CVE-2026-27630 in the wild and no public exploit code.

Sources

Also known as GHSA-ccv5-8948-c99c.