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.
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History
Wed, 25 Feb 2026 23:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | TinyWeb vulnerable to Remote Denial of Service via Thread/Connection Exhaustion (Slowloris) | |
| Weaknesses | CWE-400 | |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-02-25T23:05:16.563Z
Updated: 2026-02-25T23:07:56.613Z
Reserved: 2026-02-20T22:02:30.028Z
Link: CVE-2026-27630
No data.
Status : Received
Published: 2026-02-26T00:16:23.813
Modified: 2026-02-26T00:16:23.813
Link: CVE-2026-27630
No data.