# CVE-2026-36611: Information disclosure in n/a

> Unauthenticated adjacent attackers can read uninitialized memory from Mercusys AC12G routers via malformed UPnP requests, potentially exposing sensitive internal data.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Jun 2026
- **Updated:** 3 Jun 2026
- **Also known as:** GHSA-rh54-5hmc-6qjg

## What is CVE-2026-36611?

CVE-2026-36611 is a high-severity vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Mercusys AC12G (EU) V1 with firmware AC12G(EU)_V1_200909 returns 128 bytes of uninitialized buffer when receiving POST requests without SOAPAction header on UPnP port 1900, exposing internal memory to unauthenticated adjacent network attackers.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-36611?


## How do I fix CVE-2026-36611?

No fix has been published for CVE-2026-36611 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-36611 being exploited?

There is no known exploitation of CVE-2026-36611 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-36611 and fix it if it is affected.

What it is: CVE-2026-36611 is a high-severity vulnerability in n/a, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-36611 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-2026-36611/ (Markdown: https://insights.sbomify.com/CVE-2026-36611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-36611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-36611
- OSV: https://osv.dev/vulnerability/CVE-2026-36611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-36611/
Summaries are generated and may contain mistakes; the official description above is the record.