{"id":"CVE-2025-62426","summary":"vLLM vulnerable to DoS via large Chat Completion or Tokenization requests with specially crafted `chat_template_kwargs`","details":"vLLM is an inference and serving engine for large language models (LLMs). From version 0.5.5 to before 0.11.1, the /v1/chat/completions and /tokenize endpoints allow a chat_template_kwargs request parameter that is used in the code before it is properly validated against the chat template. With the right chat_template_kwargs parameters, it is possible to block processing of the API server for long periods of time, delaying all other requests. This issue has been patched in version 0.11.1.","aliases":["GHSA-69j4-grxj-j64p","PYSEC-2026-2012"],"modified":"2026-08-12T03:51:26.632878565Z","published":"2025-11-21T01:21:29.546Z","related":["CGA-7fcp-fhxp-pvrf"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62426.json"},"references":[{"type":"WEB","url":"https://github.com/vllm-project/vllm/blob/2a6dc67eb520ddb9c4138d8b35ed6fe6226997fb/vllm/entrypoints/chat_utils.py#L1602-L1610"},{"type":"WEB","url":"https://github.com/vllm-project/vllm/blob/2a6dc67eb520ddb9c4138d8b35ed6fe6226997fb/vllm/entrypoints/openai/serving_engine.py#L809-L814"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62426.json"},{"type":"ADVISORY","url":"https://github.com/vllm-project/vllm/security/advisories/GHSA-69j4-grxj-j64p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-62426"},{"type":"FIX","url":"https://github.com/vllm-project/vllm/commit/3ada34f9cb4d1af763fdfa3b481862a93eb6bd2b"},{"type":"FIX","url":"https://github.com/vllm-project/vllm/pull/27205"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/vllm-project/vllm","events":[{"introduced":"09c7792610ada9f88bbf87d32b472dd44bf23cc2"},{"fixed":"439368496db48d8f992ba8c606a0c0b1eebbfa69"},{"introduced":"b761df963c2032144468a99bcb39a11e73e16ca4"},{"fixed":"3ada34f9cb4d1af763fdfa3b481862a93eb6bd2b"}],"database_specific":{"cpe":["cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*","cpe:2.3:a:vllm:vllm:0.11.1:rc0:*:*:*:*:*:*","cpe:2.3:a:vllm:vllm:0.11.1:rc1:*:*:*:*:*:*"],"extracted_events":[{"introduced":"0.5.5"},{"fixed":"0.11.1"},{"introduced":"0.11.1-rc0"},{"last_affected":"0.11.1-rc0"},{"introduced":"0.11.1-rc1"},{"last_affected":"0.11.1-rc1"}],"source":["CPE_RANGE","CPE_STRING","REFERENCES"]}}],"versions":["0.11.1-rc0","0.11.1-rc1","v0.11.1rc6","v0.11.1rc5","v0.11.1rc4","v0.11.1rc3","v0.11.1rc2","v0.11.1rc1","v0.11.1rc0","v0.11.0rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-62426.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}