{"cve":"CVE-2026-73559","nvd":{"published":"2026-08-13T16:19:05.863","modified":"2026-09-28T18:41:23.210","status":"Analyzed","description":"vLLM is an inference and serving engine for large language models. From 0.19.0 until 0.26.0, the /v1/completions CompletionRequest.prompt field in vllm/entrypoints/openai/completion/protocol.py accepts an unbounded list[str] or list[list[int]], prompt_to_seq() in vllm/renderers/inputs/preprocess.py and OnlineRenderer.preprocess_completion() in vllm/renderers/online_renderer.py expand every element, and vllm/entrypoints/openai/completion/serving.py creates one engine generator and response slot per prompt, allowing an authenticated API client to exhaust CPU, memory, async scheduling capacity, engine request slots, and response buffering with one request. This issue is fixed in version 0.26.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-400"],"references":["https://github.com/vllm-project/vllm/commit/675f4295cdfe0d870471c2b51bfeca3a68a9569e","https://github.com/vllm-project/vllm/pull/47845","https://github.com/vllm-project/vllm/releases/tag/v0.26.0","https://github.com/vllm-project/vllm/security/advisories/GHSA-87x5-vmc3-756j","https://github.com/vllm-project/vllm/security/advisories/GHSA-87x5-vmc3-756j"],"products":["vllm:vllm"],"source":"nvd","synced_at":"2026-10-19T22:48:17.459049833+00:00"},"epss":{"cve":"CVE-2026-73559","score":0.00583,"percentile":0.47885,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-87x5-vmc3-756j","url":"https://osv.dev/vulnerability/GHSA-87x5-vmc3-756j","summary":"vLLM: Completion prompt lists fan out into unbounded engine requests","modified":"2026-09-10T03:50:53.507329498Z","packages":[{"ecosystem":"PyPI","name":"vllm","purl":"pkg:pypi/vllm","ranges":[">=0.19.0 <0.26.0"],"fixed":["0.26.0"]}]},{"id":"PYSEC-2026-3704","url":"https://osv.dev/vulnerability/PYSEC-2026-3704","summary":"vLLM: Completion prompt lists fan out into unbounded engine requests","modified":"2026-08-19T12:45:08.461257184Z","packages":[{"ecosystem":"PyPI","name":"vllm","purl":"pkg:pypi/vllm","ranges":[">=0.19.0 <0.26.0"],"fixed":["0.26.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}