# CVE-2026-36607: Auth bypass in n/a

> Unauthenticated attackers on the adjacent network can brute-force passwords via the TDDP endpoint due to missing rate limiting, potentially gaining administrative access.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Jun 2026
- **Updated:** 3 Jun 2026
- **Also known as:** GHSA-66mf-3gg5-cm75

## What is CVE-2026-36607?

CVE-2026-36607 is a high-severity authentication bypass vulnerability in n/a, published on 3 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 allows unauthenticated brute-force attacks via the TDDP password change endpoint (code=10), which lacks the rate limiting applied to the login endpoint (code=7). An attacker on the adjacent network can attempt unlimited passwords without triggering account lockout.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts)

## Which versions are affected by CVE-2026-36607?


## How do I fix CVE-2026-36607?

No fix has been published for CVE-2026-36607 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-36607 being exploited?

There is no known exploitation of CVE-2026-36607 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-36607 and fix it if it is affected.

What it is: CVE-2026-36607 is a high-severity authentication bypass vulnerability in n/a, published on 3 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-36607 in the wild and no public exploit code.

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-2026-36607/ (Markdown: https://insights.sbomify.com/CVE-2026-36607/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-36607
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-36607
- OSV: https://osv.dev/vulnerability/CVE-2026-36607

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-36607/
Summaries are generated and may contain mistakes; the official description above is the record.