Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Gleam-Wisp | Wisp | >= 2.1.1, < 2.2.1 |
Related Weaknesses (CWE)
References
- https://cna.erlef.org/cves/CVE-2026-28807.htmlThird Party Advisory
- https://github.com/gleam-wisp/wisp/commit/161118c431047f7ef1ff7cabfcc38981877fddPatch
- https://github.com/gleam-wisp/wisp/security/advisories/GHSA-h7cj-j2vv-qw8rExploitPatchVendor Advisory
- https://osv.dev/vulnerability/EEF-CVE-2026-28807Third Party Advisory
FAQ
What is CVE-2026-28807?
CVE-2026-28807 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 fu...
How severe is CVE-2026-28807?
CVE-2026-28807 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-28807?
Check the references section above for vendor advisories and patch information. Affected products include: Gleam-Wisp Wisp.