# CVE-2026-78158: Open5GS AMF UEContextReleaseRequest improper authorization in RAN ownership

Source: https://junglewise.ai/threats/cve-2026-78158-open5gs-amf-uecontextreleaserequest-improper-authorization-in-ran  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-24. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-78158 · Severity: medium · CVSS 6.3 · Published 2026-08-24

Open5GS is a 5G core network implementation that manages connections between mobile devices and cellular infrastructure. A flaw in its Access and Mobility Management Function (AMF) allows an attacker on a different base station to fraudulently release another base station's mobile device contexts, potentially causing service disruption for legitimate users without authorization.

Technologies: [Open5GS](https://junglewise.ai/threats/technologies/open5gs). Vendors: [Open5GS](https://junglewise.ai/threats/vendors/open5gs).

## Quick answers

**Is CVE-2026-78158 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78158 being exploited in the wild.

**How severe is CVE-2026-78158?** Medium severity, with a CVSS score of 6.3, published 24 August 2026.

**Which products and versions are affected?** Open5GS 2.8.0.

**Is there a fix for CVE-2026-78158?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-78158 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-78158?** Check whether you run Open5GS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an improper authorization / missing ownership validation flaw in the AMF's UEContextReleaseRequest message handler. The AMF fails to verify that a UEContextReleaseRequest originates from the NG-RAN node (base station) that actually owns/controls the target UE context; instead, it accepts the request from any associated gNB. An attacker controlling a second gNB association can send a UEContextReleaseRequest with another gNB's UE NGAP identifiers, causing the AMF to release that UE's context on the original gNB association. The vulnerability is network-reachable (requires NG-RAN/NGAP protocol access) and no authentication is bypassed—the flaw is in application-level context ownership authorization logic. A patch or update has not yet been released as of the advisory date.

## Affected products

- Open5GS Open5GS 2.8.0

## Timeline

- 2026-06-26: disclosed
- 2026-08-24: advisory

## References

- [https://github.com/open5gs/open5gs/](https://github.com/open5gs/open5gs/)
- [https://github.com/open5gs/open5gs/security/advisories/GHSA-mg8r-2cvv-xq9j](https://github.com/open5gs/open5gs/security/advisories/GHSA-mg8r-2cvv-xq9j)

## Related threats

- [Open5GS HTTP/2 SBI server memory exhaustion](https://junglewise.ai/threats/cve-2026-106806-a-memory-exhaustion-issue-exists-in-open5gs-v2-8-0-in-the-http-2)
- [open5GS PFCP transaction handling denial of service](https://junglewise.ai/threats/cve-2026-106807-a-denial-of-service-vulnerability-exists-in-open5gs-v2-8-0-in)
- [Open5GS heap out-of-bounds write in multipart parsing](https://junglewise.ai/threats/cve-2026-116543-open5gs-1-3-0-through-2-8-0-contains-a-heap-out-of-bounds-write)
- [Open5GS assertion failure in SGSN context request handling](https://junglewise.ai/threats/cve-2026-108105-open5gs-through-2-8-0-contains-a-reachable-assertion)
- [Open5GS heap out-of-bounds read in PFCP parsing](https://junglewise.ai/threats/cve-2026-108103-open5gs-through-2-8-0-contains-a-heap-out-of-bounds-read)