High severity · published Feb 25, 2026
CVE-2026-27630
TinyWeb vulnerable to Remote Denial of Service via Thread/Connection Exhaustion (Slowloris)
7.5
CVSS
0.5%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TI
TinyWeb · maximmasiutin
< 2.02 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27630
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27630
Patch
https://github.com/maximmasiutin/TinyWeb/commit/23268c8
Vendor Advisory
https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-ccv5-8948-c99c
Third Party Advisory
https://www.masiutin.net/tinyweb-cve-2026-27630.html
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