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CVE-2026-71486

Full vulnerability record from the local CVENow database.

Description

vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the /v1/completions/derender and /v1/chat/completions/derender endpoints accept caller-supplied GenerateResponse objects whose generate_responses, choices, token_ids, prompt_logprobs, logprobs.content, top_logprobs, and routed_experts structures are processed by OnlineDerenderer and tokenizer.decode before max_model_len, max_tokens, max_num_seqs, or response-size limits are enforced, allowing an authenticated API client to consume excessive CPU and memory and produce oversized responses. This issue is fixed in version 0.26.0.

Severity
MEDIUM
CVSS score
4.3 (v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-08-17 20:16:45.927000
Last modified
2026-10-23 16:10:00.313000
View original CVE JSON
{
  "id": "CVE-2026-71486",
  "sourceIdentifier": "[email protected]",
  "published": "2026-08-17T20:16:45.927",
  "lastModified": "2026-10-23T16:10:00.313",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the /v1/completions/derender and /v1/chat/completions/derender endpoints accept caller-supplied GenerateResponse objects whose generate_responses, choices, token_ids, prompt_logprobs, logprobs.content, top_logprobs, and routed_experts structures are processed by OnlineDerenderer and tokenizer.decode before max_model_len, max_tokens, max_num_seqs, or response-size limits are enforced, allowing an authenticated API client to consume excessive CPU and memory and produce oversized responses. This issue is fixed in version 0.26.0."
    },
    {
      "lang": "es",
      "value": "vLLM es un motor de inferencia y servicio para grandes modelos de lenguaje. Antes de la versión 0.26.0, los puntos finales /v1/completions/derender y /v1/chat/completions/derender aceptan objetos GenerateResponse proporcionados por el llamador cuyas estructuras generate_responses, choices, token_ids, prompt_logprobs, logprobs.content, top_logprobs y routed_experts son procesadas por OnlineDerenderer y tokenizer.decode antes de que se apliquen los límites de max_model_len, max_tokens, max_num_seqs o tamaño de respuesta, permitiendo a un cliente API autenticado consumir CPU y memoria excesivas y producir respuestas sobredimensionadas. Este problema se corrige en la versión 0.26.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "vllm-project",
          "product": "vllm",
          "versions": [
            {
              "version": "< 0.26.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-08-18T12:34:35.419144Z",
          "id": "CVE-2026-71486",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "0.26.0",
              "matchCriteriaId": "BB265B9E-EBAE-4833-8C3E-B203C8E9EC86"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/vllm-project/vllm/commit/8e61b646e2d157f9b93451fa048f9c8530c8a67b",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/vllm-project/vllm/pull/47260",
      "source": "[email protected]",
      "tags": [
        "Issue Tracking",
        "Patch"
      ]
    },
    {
      "url": "https://github.com/vllm-project/vllm/releases/tag/v0.26.0",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/vllm-project/vllm/security/advisories/GHSA-8737-qx52-hjff",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory",
        "Mitigation"
      ]
    }
  ]
}