FKIE_CVE-2026-107286

Vulnerability from fkie_nvd - Published: 2026-10-08 15:17 - Updated: 2026-10-08 20:35
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 2.10.0 until 2.53.0, streamed requests made through ConcurrencyLimitedModel or limit_model_concurrency can retain shared concurrency slots because anyio.CapacityLimiter associates an acquired slot with the borrowing task while streaming cleanup can run in a different task. Early stream termination, cancellation, consumer exceptions, or complete stream_text() consumption with debounce_by=0.1 can therefore leave capacity occupied, eventually preventing later requests that share the long-lived limiter from proceeding and causing a denial of service. Agent-level max_concurrency and non-streaming model requests are not affected. This issue is fixed in version 2.53.0.
References
security-advisories@github.comhttps://github.com/pydantic/pydantic-ai/commit/453f19feeb7ab1d789f9393b1723c6a73b3d77b2
security-advisories@github.comhttps://github.com/pydantic/pydantic-ai/pull/9478
security-advisories@github.comhttps://github.com/pydantic/pydantic-ai/releases/tag/v2.53.0
security-advisories@github.comhttps://github.com/pydantic/pydantic-ai/security/advisories/GHSA-6fqq-452j-qhrp
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "pydantic-ai",
          "vendor": "pydantic",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.10.0, \u003c 2.53.0"
            }
          ]
        },
        {
          "product": "pydantic-ai-slim",
          "vendor": "pydantic",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.10.0, \u003c 2.53.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 2.10.0 until 2.53.0, streamed requests made through ConcurrencyLimitedModel or limit_model_concurrency can retain shared concurrency slots because anyio.CapacityLimiter associates an acquired slot with the borrowing task while streaming cleanup can run in a different task. Early stream termination, cancellation, consumer exceptions, or complete stream_text() consumption with debounce_by=0.1 can therefore leave capacity occupied, eventually preventing later requests that share the long-lived limiter from proceeding and causing a denial of service. Agent-level max_concurrency and non-streaming model requests are not affected. This issue is fixed in version 2.53.0."
    }
  ],
  "id": "CVE-2026-107286",
  "lastModified": "2026-10-08T20:35:31.200",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-107286",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-08T17:26:50.651820Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-08T15:17:40.753",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/pydantic/pydantic-ai/commit/453f19feeb7ab1d789f9393b1723c6a73b3d77b2"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/pydantic/pydantic-ai/pull/9478"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/pydantic/pydantic-ai/releases/tag/v2.53.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-6fqq-452j-qhrp"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-772"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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