What’s Vulnerable › Vulnerabilities

CVE-2026-102634: SGLang through 0.5.20 Denial of Service via Duplicate bootstrap_room

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-29 · updated 2026-09-29
• Weakness: CWE-694

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

• SGLang: through 0.5.20

References

• https://github.com/sgl-project/sglang
• https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/conn.py#L392-L393
• https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/decode.py#L942
• https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/mooncake/conn.py#L2760-L2764
• https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/managers/io_struct.py#L281
• https://github.com/sgl-project/sglang/issues/40125
• https://www.vulncheck.com/advisories/sglang-through-0.5.20-denial-of-service-via-duplicate-bootstrap-room
• https://github.com/sgl-project/sglang/issues/40125

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