CVE-2026-28807

Description

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal. 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. 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. This issue affects wisp: from 2.1.1 before 2.2.1.

Weakness classification

• 6b3ad84c-e1a6-4bf7-a703-f496b71e49db: CWE-22

Primary references

• 6b3ad84c-e1a6-4bf7-a703-f496b71e49db — Third Party Advisory
• 6b3ad84c-e1a6-4bf7-a703-f496b71e49db — Patch
• 6b3ad84c-e1a6-4bf7-a703-f496b71e49db — Exploit, Patch, Vendor Advisory
• 6b3ad84c-e1a6-4bf7-a703-f496b71e49db — Third Party Advisory