# CVE-2026-8731: Open5GS NRF client.c ogs_sbi_client_add denial of service

> Remote attackers can cause a denial of service in Open5GS NRF by manipulating arguments in the client addition function.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 May 2026
- **Updated:** 18 May 2026
- **Also known as:** GHSA-qq7j-v673-3qjh

## What is CVE-2026-8731?

CVE-2026-8731 is a medium-severity denial of service vulnerability in Open5gs Open5gs, published on 17 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability has been found in Open5GS up to 2.7.7. Affected is the function ogs_sbi_client_add in the library /lib/sbi/client.c of the component NRF. The manipulation of the argument client_pool leads to denial of service. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-8731?

It affects 1 product.


Products: Open5gs Open5gs.

## How do I fix CVE-2026-8731?

No fix has been published for CVE-2026-8731 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8731 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8731 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-2026-8731 and fix it if it is affected.

What it is: CVE-2026-8731 is a medium-severity denial of service vulnerability in Open5gs Open5gs, published on 17 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8731 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-2026-8731/ (Markdown: https://insights.sbomify.com/CVE-2026-8731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8731
- OSV: https://osv.dev/vulnerability/CVE-2026-8731

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8731/
Summaries are generated and may contain mistakes; the official description above is the record.