Vulnerability · Published Sep 29, 2026 · Assigned by VulnCheck
CVE-2026-102634SGLang through 0.5.20 Denial of Service via Duplicate bootstrap_room
High 7.5
In plain English
A high-severity security flaw in sglang from sgl-project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 52.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
SGLang through 0.5.20 in prefill/decode disaggregation mode fails to validate duplicate bootstrap_room fields in /generate requests with Mooncake KV transfer backend. Unauthenticated attackers can send concurrent requests with identical bootstrap_room values to crash scheduler processes or hang other users' requests until transfer timeout.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| sgl-project | sglang | 0 – through 0.5.20 |
Weakness: CWE-694 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- GitHub Issue #40125 issue-tracking
- https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/conn.py#L392-L393 technical-description
- https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/mooncake/conn.py#L2760-L2764 technical-description
- https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/decode.py#L942 technical-description
- https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/managers/io_struct.py#L281 technical-description
- https://github.com/sgl-project/sglang product
- VulnCheck Advisory: SGLang through 0.5.20 Denial of Service via Duplicate bootstrap_room third-party-advisory