CVE-2026-28807
Severity CVSS v4.0:
HIGH
Type:
CWE-22
Path Traversal
Publication date:
10/03/2026
Last modified:
11/03/2026
Description
Improper Limitation of a Pathname to a Restricted Directory (&#39;Path Traversal&#39;) vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.<br />
<br />
The wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.<br />
<br />
An unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.<br />
<br />
This issue affects wisp: from 2.1.1 before 2.2.1.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH