CVE-2025-15532 is a vulnerability identified in the Open5GS project, an open-source implementation of the 5G core network. The flaw exists in the Timer Handler component, where certain processing can be manipulated remotely to cause excessive resource consumption. This can lead to denial-of-service (DoS) conditions by exhausting system resources such as CPU or memory, degrading or halting the affected network functions. The vulnerability affects Open5GS versions 2.7.0 through 2.7.5. Exploitation does not require any authentication or user interaction, and the attack vector is network-based, making it accessible to remote attackers. The vulnerability has a CVSS 4.0 base score of 6.9, indicating medium severity. The exploit has been publicly released, increasing the likelihood of exploitation in the wild. The patch to fix this issue is identified by commit c7c131f8d2cb1195ada5e0e691b6868ebcd8a845, which should be applied to vulnerable systems. Open5GS is used by telecom operators and enterprises deploying 5G core networks, making this vulnerability significant for the availability of critical telecom infrastructure.

The primary impact of CVE-2025-15532 is on the availability of 5G core network services implemented with Open5GS. Successful exploitation can lead to resource exhaustion, causing denial-of-service conditions that disrupt network functions such as session management, mobility management, and subscriber data handling. This can degrade service quality or cause outages affecting end-users and enterprise customers relying on 5G connectivity. Given that Open5GS is used in production environments by telecom operators and private 5G deployments, the vulnerability poses a risk to critical communication infrastructure. The public availability of an exploit increases the risk of opportunistic attacks, potentially leading to service disruptions or cascading failures in dependent systems. While confidentiality and integrity are not directly impacted, the loss of availability in telecom networks can have wide-reaching operational and economic consequences.

To mitigate CVE-2025-15532, organizations should immediately apply the official patch identified by commit c7c131f8d2cb1195ada5e0e691b6868ebcd8a845 to all affected Open5GS instances. In addition to patching, network operators should implement rate limiting and anomaly detection on traffic directed at the Timer Handler component to detect and block suspicious patterns indicative of resource exhaustion attempts. Deploying robust monitoring of system resource usage and alerting on abnormal spikes can provide early warning of exploitation attempts. Network segmentation and strict access controls should be enforced to limit exposure of Open5GS management interfaces to untrusted networks. Regularly updating Open5GS and related components to the latest stable versions will reduce exposure to known vulnerabilities. Finally, conducting penetration testing and resilience assessments on 5G core network deployments can help identify and remediate similar resource consumption issues proactively.