TI-2026-21887 Aliases CVE-2026-27480 GHSA-qhp6-635j-x7r2

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

MEDIUM 63CWE-204Published 2026-02-21 · Updated 2026-02-24

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-204.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00394 33rd percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed static-web-server (static-web-server): 2.41.0static-web-server (crates.io): 2.41.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
static-web-server	static-web-server	2.1.0 to before 2.41.0	2.41.0	Patch available	CNA
—	static-web-server (crates.io)	2.1.0 to before 2.41.0	2.41.0	Patch available	GHSA-qhp6-635j-x7r2

static-web-server Vendorstatic-web-server Affected 2.1.0 to before 2.41.0 Fixed in 2.41.0 Patch available CNA
static-web-server (crates.io) Vendor— Affected 2.1.0 to before 2.41.0 Fixed in 2.41.0 Patch available GHSA-qhp6-635j-x7r2

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:static-web-server:static_web_server::::::rust::*	2.1.0 to before 2.41.0	Vulnerable	static-web-server

cpe:2.3:a:static-web-server:static_web_server:*:*:*:*:*:rust:*:* Versions 2.1.0 to before 2.41.0 Vulnerable ·static-web-server

Remediation

Fix · CNA static-web-server (static-web-server) Fixed in 2.41.0
Fix · GHSA-qhp6-635j-x7r2 static-web-server (crates.io) Fixed in 2.41.0 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-27480
2026-10-03 Alias added: GHSA-qhp6-635j-x7r2

References

TI-2025-41246 Static Web Server is vulnerable to symbolic link Path Traversal CVSS 4.0MEDIUM 5.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences