CVE-2026-59928

{
  "id": "CVE-2026-59928",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-08T17:17:28.600",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0."
    },
    {
      "lang": "es",
      "value": "Mistune es un analizador de Markdown para Python con renderizadores y complementos. Antes de la versión 3.3.0, un documento Markdown que contiene muchas definiciones de enlaces de referencia repetidas o distintas causa un trabajo cuadrático en src/mistune/block_parser.py y en el manejo del diccionario de entorno ref_links, lo que permite la denegación de servicio mediante el agotamiento de la CPU. Este problema se solucionó en la versión 3.3.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "lepture",
          "product": "mistune",
          "versions": [
            {
              "version": "< 3.3.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-08T17:46:13.539153Z",
          "id": "CVE-2026-59928",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-407"
        },
        {
          "lang": "en",
          "value": "CWE-1333"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "3.3.0",
              "matchCriteriaId": "63E1B933-D2E2-44EF-A56C-94483300845B"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/lepture/mistune/commit/2b04d7ba341c16ac78fe82d3076bdd5c3de87c69",
      "source": "[email protected]",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://github.com/lepture/mistune/releases/tag/v3.3.0",
      "source": "[email protected]",
      "tags": [
        "Release Notes"
      ]
    },
    {
      "url": "https://github.com/lepture/mistune/security/advisories/GHSA-ffq3-xpv3-j92q",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://github.com/lepture/mistune/security/advisories/GHSA-ffq3-xpv3-j92q",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    }
  ]
}