High severity · published Sep 29, 2026
CVE-2026-102634
SGLang through 0.5.20 Denial of Service via Duplicate bootstrap_room
7.5
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SG
sglang · sgl-project
through 0.5.20 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-102634
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-102634
issue-tracking
https://github.com/sgl-project/sglang/issues/40125
technical-description
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
product
https://github.com/sgl-project/sglang
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