CVE-2026-7781 Open5GS amf-3gpp-access Endpoint nudm-handler.c udm_nudm_uecm_handle_amf_registration_update denial of service
Remote attackers can cause a denial of service in Open5GS via the AMF registration update handler, requiring immediate attention from 5G network operators.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-7781?
CVE-2026-7781 is a medium-severity denial of service vulnerability in Open5GS, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A security vulnerability has been detected in Open5GS up to 2.7.7. Affected by this issue is the function udm_nudm_uecm_handle_amf_registration_update of the file /src/udm/nudm-handler.c of the component amf-3gpp-access Endpoint. The manipulation leads to denial of service. The attack is possible to be carried out remotely. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.
Weakness: CWE-404
Which versions are affected by CVE-2026-7781?
How do I fix CVE-2026-7781?
No fix has been published for CVE-2026-7781 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-7781 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-7781 exists.
Sources
Also known as GHSA-j7cf-vfq9-rhmh.