CVE-2026-27633

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 have a Denial of Service (DoS) vulnerability via memory exhaustion. Unauthenticated remote attackers can send an HTTP POST request to the server with an exceptionally large `Content-Length` header (e.g., `2147483647`). The server continuously allocates memory for the request body (`EntityBody`) while streaming the payload without enforcing any maximum limit, leading to all available memory being consumed and causing the server to crash. Anyone hosting services using TinyWeb is impacted. Version 2.02 fixes the issue. The patch introduces a `CMaxEntityBodySize` limit (set to 10MB) for the maximum size of accepted payloads. As a temporary workaround if upgrading is not immediately possible, consider placing the server behind a Web Application Firewall (WAF) or reverse proxy (like nginx or Cloudflare) configured to explicitly limit the maximum allowed HTTP request body size (e.g., `client_max_body_size` in nginx).

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/1cb5a1d
    Patch
  • github.com https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-992w-gmcm-fmgr
    Vendor Advisory
  • masiutin.net https://www.masiutin.net/tinyweb-cve-2026-27633.html
    Third Party Advisory

Remediation

  • github.com https://github.com/maximmasiutin/TinyWeb/commit/1cb5a1d
    Patch