CVE-2026-56676 9router: Image prefetch DNS rebinding allows SSRF to internal services
An authenticated attacker can exploit DNS rebinding in image prefetching to access internal services via the AI router proxy.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-56676?
CVE-2026-56676 is a high-severity server-side request forgery vulnerability in decolua 9router, published on 10 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
9Router is an AI router & token saver. Prior to 0.5.2, 9router validates image URLs by resolving the host before fetching, but open-sse/translator/concerns/image.js performs the later server-side image fetch with a separate DNS resolution. An authenticated attacker with access to the LLM proxy can use a vision-capable model and an attacker-controlled DNS name that first resolves to a public IP and then rebinds to an internal address, allowing server-side requests to internal-only HTTP services. This issue is fixed in version 0.5.2.
Which versions are affected by CVE-2026-56676?
2 open source packages ship an affected version, including 9router.
| Package | Affected | Fixed in |
|---|---|---|
9router npm | All versions | 0.5.2 |
9router npm | All versions | 0.5.2 |
How do I fix CVE-2026-56676?
Upgrade 9router to 0.5.2 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-56676 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56676 exists.
Sources
Also known as GHSA-cmhj-wh2f-9cgx.