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CVE-2026-100647— vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt

Quick assessment

Affected
vllm-project vllm
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

vLLM 版本低于 0.29.0 的实例中存在一个拒绝服务漏洞，该漏洞出现在对 OpenAI 兼容和 Anthropic API 端点所接受的 参数处理过程中。由于缺乏最大长度验证，且该参数在单一 EngineCore 调度器线程上进行处理，未授权的攻击者可以发送包含数百兆字节 salt 值的 HTTP 请求，从而触发昂贵的 pickle 序列化与 SHA-256 哈希计算，导致调度器线程被阻塞，进而使所有并发请求无法获得服务。

CVSS 5.3 · Medium EPSS 0.31% · P21
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I. Basic Information for CVE-2026-100647

Vulnerability Information
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Vulnerability Title
vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt
Source: CVE Program / CVE List V5
Vulnerability Description
vLLM versions before 0.29.0 contain a denial-of-service vulnerability in the cache_salt parameter accepted on OpenAI-compatible and Anthropic API endpoints, which lacks maximum length validation and is processed on the single EngineCore scheduler thread. Unauthenticated attackers can send HTTP requests with multi-hundred-megabyte salt values that trigger expensive pickle serialization and SHA-256 hashing, stalling the scheduler thread and denying service to all concurrent requests.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
输入验证不恰当
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
vllm-project vllm 0 ~ 0.29.0 -

II. Public POCs for CVE-2026-100647

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III. Intelligence Information for CVE-2026-100647

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Vendor Advisories for CVE-2026-100647 (1)

Other References for CVE-2026-100647 (1)

Same Patch Batch · vllm-project · 2026-09-26 · 8 CVEs total

CVE-2026-100654 6.5 MEDIUM vLLM before 0.29.0 Denial of Service via out-of-range stop_token_ids
CVE-2026-100650 6.5 MEDIUM vLLM before 0.29.0 Resource Exhaustion via Unbounded Media Materialization
CVE-2026-100651 6.5 MEDIUM vllm before 0.29.0 Denial of Service via Decoder Prompt Length Bypass
CVE-2026-100653 6.5 MEDIUM vLLM 0.22.1 before 0.28.0 Incomplete Artifact Pin Propagation
CVE-2026-100652 5.9 MEDIUM vLLM 0.22.0 through 0.23.0 Denial of Service via stop_token_ids
CVE-2026-100648 5.3 MEDIUM vllm before 0.29.0 Uncontrolled Resource Consumption via Audio Decoding
CVE-2026-100649 3.7 LOW vLLM before 0.29.0 Resource Limit Bypass via Sampler Subclass

IV. Related Vulnerabilities

Same product: vllm
Same vendor: vllm-project
Same weakness: CWE-20

V. Comments for CVE-2026-100647

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