CVE-2026-8731: Open5GS NRF client.c ogs_sbi_client_add denial of service
A vulnerability has been found in Open5GS up to 2.7.7. Affected is the function ogssbiclientadd in the library /lib/sbi/client.c of the component NRF. The manipulation of the argument clientpool 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Restrict network access to the Open5GS NRF SBI endpoints (the service exposing ogs_sbi_client_add) to trusted IP ranges using firewall rules, ACLs or network segmentation so the component is not directly reachable from untrusted networks.
- Compensating control
Place rate limiting, connection limits, or a WAF in front of the NRF SBI interface to mitigate remote denial-of-service attempts that exploit the client_pool manipulation.
- Operational
Monitor NRF process health and SBI-related logs for crashes, repeated client creation failures or anomalous requests; enable alerting and collect detailed logs/forensics if exploitation is suspected.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-8731?
The severity of CVE-2026-8731 is classified as a denial of service vulnerability.
How do I fix CVE-2026-8731?
To fix CVE-2026-8731, upgrade Open5GS to a version later than 2.7.7.
Which versions of Open5GS are affected by CVE-2026-8731?
Open5GS versions up to and including 2.7.7 are affected by CVE-2026-8731.
What component of Open5GS is impacted by CVE-2026-8731?
The impacted component in Open5GS related to CVE-2026-8731 is the NRF client in the library /lib/sbi/client.c.
Can CVE-2026-8731 lead to system downtime?
Yes, CVE-2026-8731 can lead to system downtime due to its denial of service nature.