Vulnerability · Published Sep 18, 2026 · Assigned by VulnCheck

CVE-2026-93688SGLang through 0.5.19 Unbounded Memory Allocation via bootstrap_room

High 7.5

In plain English

A high-severity resource allocation without limits in sglang from sgl-project. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.7%top 45.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

SGLang through 0.5.19 in prefill/decode disaggregation mode with Mooncake KV transfer backend fails to validate bootstrap_room values, allowing unbounded transfer state allocation. Unauthenticated attackers can reach the decode engine's POST /generate endpoint and submit arbitrary bootstrap_room values to exhaust prefill process memory until out-of-memory termination.

Affected products (as reported)

Vendor	Product	Versions
sgl-project	sglang	0 – through 0.5.19

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

GitHub Issue #39428 issue-tracking
https://github.com/sgl-project/sglang product
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L2118-L2119 technical-description
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L1988-L1990 technical-description
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/io_struct.py#L281 technical-description
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/scheduler.py#L2672-L2690 technical-description
VulnCheck Advisory: SGLang through 0.5.19 Unbounded Memory Allocation via bootstrap_room third-party-advisory