CVE-2026-93688: SGLang through 0.5.19 Unbounded Memory Allocation via bootstrap_room
SGLang through 0.5.19 in prefill/decode disaggregation mode with Mooncake KV transfer backend fails to validate bootstraproom values, allowing unbounded transfer state allocation. Unauthenticated attackers can reach the decode engine's POST /generate endpoint and submit arbitrary bootstraproom values to exhaust prefill process memory until out-of-memory termination.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Deployments of SGLang through 0.5.19 are affected when they use prefill/decode disaggregation mode with the Mooncake KV transfer backend and expose the decode engine's POST /generate endpoint to unauthenticated requests.
What does an attacker need to exploit it?
An attacker only needs network access to the decode engine's POST /generate endpoint. No authentication or user interaction is required, and the attacker can supply arbitrary bootstrap_room values.
What is the practical impact of successful exploitation?
Repeated or sufficiently large bootstrap_room values can cause unbounded transfer-state memory allocation in the prefill process. This can exhaust memory and terminate the process due to an out-of-memory condition.