CVE-2026-100647CWE-20

CVE-2026-100647

Medium · published September 26, 2026

CVSS v3.1
5.3
EPSS
0%
Percentile
27.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v4.0
6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00348 · 27.2th percentile
Weakness
CWE-20 · Improper Input Validation
Published
2026-09-26T18:16Z
Affected products (1)
ProductVersionsFixed in
vllm/vllm< 0.29.00.29.0
References (2)
https://github.com/vllm-project/vllm/security/advisories/GHSA-wpww-v874-ph2p · [email protected]https://www.vulncheck.com/advisories/vllm-before-0.29.0-cpu-exhaustion-via-unbounded-cache-salt · [email protected]
EPSS history
Timeline
  • 28 SEP 03:25Z
    EPSS moved — → 0%
    epss
  • 26 SEP 13:23Z
    vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt
    cvelistv5