CVE-2026-27480 MEDIUM

CVE-2026-27480: Static Web Server: Timing-Based Username Enumeration in Basic Authentication

Vendor Static-Web-Server
Product static-web-server
Weakness CWE-204
Published February 21, 2026
Last update February 24, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

Static Web Server (SWS) is a production-ready web server suitable for static web files or assets. In versions 2.1.0 through 2.40.1, a timing-based username enumeration vulnerability in Basic Authentication allows attackers to identify valid users by exploiting early responses for invalid usernames, enabling targeted brute-force or credential-stuffing attacks. SWS checks whether a username exists before verifying the password, causing valid usernames to follow a slower code path (e.g., bcrypt hashing) while invalid usernames receive an immediate 401 response. This timing discrepancy allows attackers to enumerate valid accounts by measuring response-time differences. This issue has been fixed in version 2.41.0.

Key dates

02Disclosure timeline

February 21, 2026 CVE published
February 24, 2026 Record updated