An authorization bypass flaw exists in sglang-router (sgl-model-gateway) versions up to 0.3.2. The flaw allows any actor that possesses a data‑plane API key to access /ha/* endpoints, which bypass the control‑plane Admin role checks. Through these endpoints the actor can read the cluster’s topology, modify gossiped configuration, adjust global rate limits, and issue a POST to /ha/shutdown to quietly end high‑availability coordination. Thus the vulnerability threatens confidentiality, integrity, and availability of the mesh network, allowing an attacker to effectively hijack administrative functions.

The affected product is sgl-lang‑router (sgl-model-gateway) from the sgl‑project. All releases through 0.3.2 are vulnerable; newer releases contain the fix. Specific version information is only available for the affected range, not for later versions.

CVSS score is 5.3, indicating a moderate severity. EPSS data is not available, and the vulnerability is not listed in the CISA KEV catalog. The attack requires possession of a valid data‑plane API key; based on the description, it is inferred that a key could be obtained through compromised services or credential leakage. Once the key is in hand, the bypass allows direct administrative actions without the usual Admin role checks.