# CVE-2026-8746: Open5GS NRF nghttp2-server.c discover_handler use after free

> Remote attackers can exploit a use-after-free flaw in Open5GS NRF to potentially execute code or cause denial of service.

- **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-49g8-77wh-w2gp

## What is CVE-2026-8746?

CVE-2026-8746 is a medium-severity use after free 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 security flaw has been discovered in Open5GS up to 2.7.7. Affected by this issue is the function discover_handler in the library /lib/sbi/nghttp2-server.c of the component NRF. The manipulation results in use after free. The attack can be launched remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-416 (Use After Free), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-8746?

It affects 1 product.


Products: Open5gs Open5gs.

## How do I fix CVE-2026-8746?

No fix has been published for CVE-2026-8746 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8746 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8746 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-2026-8746 and fix it if it is affected.

What it is: CVE-2026-8746 is a medium-severity use after free 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-2026-8746 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-2026-8746/ (Markdown: https://insights.sbomify.com/CVE-2026-8746/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8746
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8746
- OSV: https://osv.dev/vulnerability/CVE-2026-8746

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8746/
Summaries are generated and may contain mistakes; the official description above is the record.