SGLang through 0.5.19 Unbounded Memory Allocation via bootstrap_room
Priority MEDIUM 45CWE-770Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0072 54th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| sgl-project | sglang | up to 0.5.19 | — | No fix listed | CNA |
- sglang Vendorsgl-project Affected up to 0.5.19 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-93688
- 2026-10-03 Alias added: GHSA-hpqj-j2xw-q3cx
References
Other 6
- GitHub Issue #39428
- https://github.com/sgl-project/sglang
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L2118-L2119
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L1988-L1990
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/io_struct.py#L281
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/scheduler.py#L2672-L2690
More sgl-project vulnerabilities
- TI-2026-76247 Denial of service in SGLang expert-distribution recording endpoint CVSS 4.0HIGH 8.7
- TI-2026-70996 SGLang disables decompression bomb check, enabling denial of service CVSS 4.0HIGH 8.7
- TI-2026-70994 SGLang Memory Exhaustion DoS via Qwen-VL Video Preprocessing CVSS 4.0HIGH 8.7
- TI-2026-70993 Decompression amplification in SGLang load_audio exhausts memory CVSS 4.0HIGH 8.7
- TI-2026-65453 SGLang through 0.5.20 Denial of Service via Duplicate bootstrap_room CVSS 4.0HIGH 8.7
- TI-2026-75290 Code injection in SGLang debug dumper filter CVSS 4.0CRITICAL 9.2
Sources
- CVE-2026-93688 · CVE Program
- CVE-2026-93688 · NVD
- FIRST EPSS
- GHSA-hpqj-j2xw-q3cx · GitHub Advisory Database · CC BY 4.0
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