Disclosure summary
Koa is expressive middleware for Node.js using ES2017 async functions. In versions 2.16.2 to before 2.16.3 and 3.0.1 to before 3.0.3, a bypass to CVE-2025-8129 was discovered in the Koa.js framework affecting its back redirect functionality. In certain circumstances, an attacker can manipulate the Referer header to force a user’s browser to navigate to an external, potentially malicious website. This occurs because the implementation incorrectly treats some specially crafted URLs as safe relative paths. Exploiting this vulnerability could allow attackers to perform phishing, social engineering, or other redirect-based attacks on users of affected applications. This issue has been patched in version 3.0.3.
Source-reported weakness categories
CWE-601
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2025-62595
Open original source · Updated Oct 08, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| koajs | koa | * {"versionStartIncluding":"3.0.1","versionEndExcluding":"3.0.3"} |
| koajs | koa | 2.16.2 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Patch
- github.com — Exploit, Vendor Advisory
- github.com — Exploit, Vendor Advisory
PUBLISHED 2025-10-21T13:15:40-04:00
MODIFIED 2026-10-08T07:10:00-04:00
INGESTED 2026-10-08T12:30:43-04:00