CVE-2025-8129 KoaJS Koa HTTP Header response.js back redirect
Attackers can exploit an open redirect in the KoaJS framework's HTTP header handler to redirect users to malicious sites.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-8129?
CVE-2025-8129 is a medium-severity vulnerability in KoaJS Koa, published on 25 Jul 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A vulnerability, which was classified as problematic, was found in KoaJS Koa up to 3.0.0. Affected is the function back in the library lib/response.js of the component HTTP Header Handler. The manipulation of the argument Referrer leads to open redirect. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
Weakness: CWE-601
Which versions are affected by CVE-2025-8129?
4 open source packages ship an affected version, including koa. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
koa npm | From 2.0.0 | 2.16.2 |
koa npm | From 2.0.0 | 2.16.2 |
koa npm | From 3.0.0-alpha.0 | 3.0.1 |
koa npm | From 3.0.0-alpha.0 | 3.0.1 |
Products include Koajs Koa.
How do I fix CVE-2025-8129?
Upgrade koa to a fixed version for your release line: 2.16.2 or 3.0.1.
Is CVE-2025-8129 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-8129 exists.
Other vulnerabilities in KoaJS Koa
Sources
Also known as CVE-2025-54420, GHSA-jgmv-j7ww-jx2x, ROOT-APP-NPM-CVE-2025-8129.