# CVE-2026-33904: Ella Core has a Denial of Service via SCTP connection cleanup deadlock

> An attacker with N2 interface access can trigger a deadlock in Ella Core's AMF, causing a denial of service for all subscribers.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 31 Mar 2026
- **Also known as:** GHSA-9h59-p45g-445h, GO-2026-4874

## What is CVE-2026-33904?

CVE-2026-33904 is a medium-severity denial of service vulnerability in ellanetworks core, published on 27 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Ella Core is a 5G core designed for private networks. Prior to version 1.7.0, a deadlock in the AMF's SCTP notification handler causes the entire AMF control plane to hang until the process is restarted. An attacker with access to the N2 interface can cause Ella Core to hang, resulting in a denial of service for all subscribers. Version 1.7.0 adds deferred Radio cleanup in serveConn SCTP server so that every connection exit path removes the radio. Remove the stale-entry scan from SCTP Notification handling.

Weakness: CWE-833 (Deadlock)

## Which versions are affected by CVE-2026-33904?

3 open source packages ship an affected version, including github.com/ellanetworks/core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/ellanetworks/core` | Go | All versions | 1.7.0 |
| `github.com/ellanetworks/core` | Go | All versions | 1.7.0 |
| `github.com/ellanetworks/core` | Go | All versions | 1.7.0 |

Products: Ellanetworks Ella Core.

## How do I fix CVE-2026-33904?

Upgrade github.com/ellanetworks/core to 1.7.0 or later.

## Is CVE-2026-33904 being exploited?

There is no known exploitation of CVE-2026-33904 in the wild and no public exploit code.

## Other vulnerabilities in ellanetworks core

- [CVE-2026-33282](https://insights.sbomify.com/CVE-2026-33282/): Ella Core panics on malformed NGAP Location Report (high 7.5)
- [CVE-2026-32319](https://insights.sbomify.com/CVE-2026-32319/): Ella Core: Unauthenticated AMF DoS via malformed InitialUEMessage with undersized integrity-protected NAS payload (high 7.5)
- [CVE-2026-33906](https://insights.sbomify.com/CVE-2026-33906/): Ella Core has Privilege Escalation via Database Restore by NetworkManager role (high 7.2)
- [CVE-2026-33903](https://insights.sbomify.com/CVE-2026-33903/): Ella Core panics when processing a crafted NGAP LocationReport message (medium 6.5)
- [CVE-2026-33907](https://insights.sbomify.com/CVE-2026-33907/): Ella Core Panics during NAS Authentication Response/Failure with missing IEs (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33904 and fix it if it is affected.

What it is: CVE-2026-33904 is a medium-severity denial of service vulnerability in ellanetworks core, published on 27 Mar 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-2026-33904 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/ellanetworks/core (Go): affected all versions; fixed in 1.7.0
- github.com/ellanetworks/core (Go): affected all versions; fixed in 1.7.0
- github.com/ellanetworks/core (Go): affected all versions; fixed in 1.7.0

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-2026-33904/ (Markdown: https://insights.sbomify.com/CVE-2026-33904/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33904
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33904
- OSV: https://osv.dev/vulnerability/CVE-2026-33904

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33904/
Summaries are generated and may contain mistakes; the official description above is the record.