# CVE-2026-36604: Security feature bypass in n/a

> An attacker can bypass CORS restrictions via DNS rebinding to access internal router resources from the internet.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Jun 2026
- **Updated:** 3 Jun 2026
- **Also known as:** GHSA-rv93-ggmg-88r9

## What is CVE-2026-36604?

CVE-2026-36604 is a medium-severity vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 does not validate the HTTP Host header, enabling DNS rebinding attacks. An external attacker can rebind a domain to the router's internal IP address, extending the CORS wildcard vulnerability (Access-Control-Allow-Origin: *) to internet-originated attacks.

Weakness: CWE-350 (Reliance on Reverse DNS Resolution for a Security-Critical Action)

## Which versions are affected by CVE-2026-36604?


## How do I fix CVE-2026-36604?

No fix has been published for CVE-2026-36604 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-36604 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-36604 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-36604 and fix it if it is affected.

What it is: CVE-2026-36604 is a medium-severity vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-36604 exists.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-36604/ (Markdown: https://insights.sbomify.com/CVE-2026-36604/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-36604
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-36604
- OSV: https://osv.dev/vulnerability/CVE-2026-36604

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-36604/
Summaries are generated and may contain mistakes; the official description above is the record.