The vulnerability resides in the CCA Message Handler component of Open5GS, specifically within the smf_gx_cca_cb, smf_gy_cca_cb, and smf_s6b functions. Malicious manipulation of these callbacks can trigger a denial‑of‑service condition, disrupting the control plane operations for affected cells. The flaw is classified as CWE‑404, indicating an improper resource shutdown or release. The impact is a loss of network connectivity for users served by the impacted SMF instance, potentially affecting all services that rely on session management.

Open5GS 2.7.6 is affected. The product is the open‑source 5G core network implementation. No other versions are listed as vulnerable in the provided data.

The CVSS score of 6.3 reflects moderate severity. Although exploitation is rated difficult and the attack is complex, the exploit has already been released publicly, meaning it may be in use. The attack vector is remote, leveraging the exposed CCA Message interfaces. Because the vulnerability is not listed in CISA's KEV catalog and EPSS data is missing, the risk assessment relies on the available score and public release; overall exposure is moderate to high for environments running the affected Open5GS version.