Telepresence is a tool that allows local developers to run code against a remote Kubernetes or OpenShift cluster. The vulnerability exists in the Traffic Manager Tunnel gRPC streaming endpoint. It parses a session ID from the first bytes of a caller‑controlled message and forwards it to state.Tunnel without verifying that the caller owns the active session. An attacker who obtains a valid session ID—through log leakage, cluster internal traffic, or the unauthenticated ArriveAsClient endpoint—can attach a tunnel to that session and gain its network routing capabilities. Because the IDs are UUID4, brute forcing them is impractical, but once an ID is known the attacker can effectively hijack the session, enabling eavesdropping, traffic manipulation, and lateral movement within the cluster.

The affected product is Telepresence by TelepresenceIO. Versions before 2.31.0 are vulnerable. Telepresence 2.31.0 and newer contain the fix. All installations of Telepresence that use the Traffic Manager Tunnel and run any earlier version are at risk.

The CVSS score of 8.2 indicates high severity. EPSS is not available and the vulnerability is not listed in CISA KEV. Exploitation requires a valid session ID, which can be obtained through log leaking or the unauthenticated ArriveAsClient endpoint. Once the ID is in hand, the hijacking is trivial because the endpoint does not verify ownership. Therefore, for vulnerable deployments the risk is high, especially in environments where logs are exposed or the ArriveAsClient endpoint is accessible from untrusted networks.