The vulnerability is located in the rls::DecodeRlsMessage function of UERANSIM’s Radio Link Simulation Layer. Manipulating the pduLength argument causes the function to throw an uncaught exception, which terminates the process. Rather than enabling arbitrary code execution, the flaw can be used to crash the service. Because the trigger can be supplied remotely, an attacker can interrupt or disrupt network functions that rely on the simulator. The weakness is an Uncaught Exception (CWE‑248), which effectively provides a Denial‑of‑Service impact.

Vendor aligungr provides UERANSIM, a software suite used for 5G radio network simulation. All releases up to and including 3.2.7 are affected. Version 3.2.8 and later contain the fix, as identified by commit ca1a66fffe282767bb08618af9f848e3b68ea47b. By updating to 3.2.8 you eliminate the code path that can trigger the uncaught exception.

The CVSS score of 6.9 places the issue in the moderate severity range. EPSS data is unavailable, and the vulnerability is not listed in the CISA KEV catalog, so large‑scale exploitation is not currently documented. However, because the flaw is remotely exploitable and can crash the simulator, organizations running UERANSIM for testing and training should consider patching immediately to avoid service disruption.