CVE-2026-27630

HIGH EPSS 34.9%
Published Feb 26, 20264mo ago · Modified Jun 17, 20261w ago
8.7 CVSS 4.0
High
Find Similar
Published Feb 26, 2026 4mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
8.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
34.9% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-400 Uncontrolled Resource Consumption Resource Mgmt
CWE-770

Affected Products 1

VendorProductVersionRange
ritlabstinyweb* <2.02

References 3

  • github.com https://github.com/maximmasiutin/TinyWeb/commit/23268c8
    Patch
  • github.com https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-ccv5-8948-c99c
    Vendor Advisory
  • masiutin.net https://www.masiutin.net/tinyweb-cve-2026-27630.html
    Third Party Advisory

Remediation

  • github.com https://github.com/maximmasiutin/TinyWeb/commit/23268c8
    Patch