# CVE-2025-5520: Open5GS AMF/MME emm_state_authentication assertion

> Remote attackers can trigger a reachable assertion in Open5GS AMF/MME components, causing a denial of service.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **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 2025
- **Updated:** 3 Jun 2025
- **Also known as:** GHSA-mqmr-5x7c-pxxx

## What is CVE-2025-5520?

CVE-2025-5520 is a medium-severity denial of service vulnerability in Open5gs Open5gs, published on 3 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was found in Open5GS up to 2.7.3. It has been classified as problematic. Affected is the function gmm_state_authentication/emm_state_authentication of the component AMF/MME. The manipulation leads to reachable assertion. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 9f5d133657850e6167231527514ee1364d37a884. It is recommended to apply a patch to fix this issue. This is a different issue than CVE-2025-1893.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2025-5520?

It affects 1 product.


Products: Open5gs Open5gs.

## How do I fix CVE-2025-5520?

No fix has been published for CVE-2025-5520 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-5520 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-5520 exists.

## Other vulnerabilities in Open5gs Open5gs

- [CVE-2024-40130](https://insights.sbomify.com/CVE-2024-40130/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-28122](https://insights.sbomify.com/CVE-2021-28122/): Missing authorization in n/a (critical 9.8)
- [CVE-2021-25863](https://insights.sbomify.com/CVE-2021-25863/): Hardcoded credentials in n/a (high 8.8)
- [CVE-2025-41067](https://insights.sbomify.com/CVE-2025-41067/): Reachable Assertion vulnerability in Open5GS (high 8.7)
- [CVE-2025-41068](https://insights.sbomify.com/CVE-2025-41068/): Reachable Assertion vulnerability in Open5GS (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-5520 and fix it if it is affected.

What it is: CVE-2025-5520 is a medium-severity denial of service vulnerability in Open5gs Open5gs, published on 3 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-5520 exists.

Affected product: Open5gs Open5gs. 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-2025-5520/ (Markdown: https://insights.sbomify.com/CVE-2025-5520/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-5520
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-5520
- OSV: https://osv.dev/vulnerability/CVE-2025-5520

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-5520/
Summaries are generated and may contain mistakes; the official description above is the record.