CVE-2026-6879

Full vulnerability record from the local CVENow database.
Description

`Element.findall()` and fully-consumed `Element.iterfind()` exhibit `O(n^2)` time complexity when using XPath index predicates (e.g. `[1]`, `[last()]`, `[last()-N]`) on XML documents with many same-tag siblings. `Element.find()` is only affected when the first match is near the end of the sibling list, such as with `[last()]` or `[last()-N]`; `.//item[1]` short-circuits after the first match.
Severity
LOW
CVSS score
2.0 (v4.0)
Vulnerability status
Awaiting Analysis
Source identifier
[email protected]
Published
2026-07-28 15:17:51.377000
Last modified
2026-10-24 13:10:00.147000
View original CVE JSON
{
  "id": "CVE-2026-6879",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-28T15:17:51.377",
  "lastModified": "2026-10-24T13:10:00.147",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "`Element.findall()` and fully-consumed `Element.iterfind()` exhibit `O(n^2)` time complexity when using XPath index predicates (e.g. `[1]`, `[last()]`, `[last()-N]`) on XML documents with many same-tag siblings. `Element.find()` is only affected when the first match is near the end  of the sibling list, such as with `[last()]` or `[last()-N]`;  `.//item[1]` short-circuits after the first match."
    },
    {
      "lang": "es",
      "value": "“Element.findall()” y “Element.iterfind()” completamente consumido exhiben una complejidad temporal de “O(n^2)” al usar predicados de índice XPath (p. ej. “[1]”, “[last()]”, “[last()-N]”) en documentos XML con muchos hermanos de la misma etiqueta. “Element.find()” solo se ve afectado cuando la primera coincidencia está cerca del final de la lista de hermanos, como con “[last()]” o “[last()-N]”; “.//item[1]” hace un cortocircuito después de la primera coincidencia."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Python Software Foundation",
          "product": "CPython",
          "defaultStatus": "unaffected",
          "repo": "https://github.com/python/cpython",
          "versions": [
            {
              "version": "0",
              "lessThan": "3.10.21",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "3.11.0",
              "lessThan": "3.11.16",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "3.12.0",
              "lessThan": "3.12.14",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "3.13.0",
              "lessThan": "3.13.15",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "3.14.0",
              "lessThan": "3.14.7",
              "versionType": "python",
              "status": "affected"
            },
            {
              "version": "3.15.0a1",
              "lessThan": "3.15.0rc1",
              "versionType": "python",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 2.0,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "HIGH",
          "userInteraction": "PASSIVE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-28T14:49:33.309576Z",
          "id": "CVE-2026-6879",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-407"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/python/cpython/commit/02c08e6b747ac43d0d866a4ffa916bedf3423f81",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/commit/037965c00a427cba5c05447efadc67c51a492e85",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/commit/0583f24ae678993e3f7939f51ad5bcae5ad9dc70",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/commit/2ffab083782968a4d732738f4f1dff6bbd69d2b0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/commit/390337b8ba1658833fdef379e1739c9f9533a8db",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/commit/96510a3758f4a075f43223afdee3b6ee1a7a7f02",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/commit/cb409342a19f25656f62e679f8bac265fe1442c3",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/issues/152674",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/python/cpython/pull/152676",
      "source": "[email protected]"
    },
    {
      "url": "https://mail.python.org/archives/list/[email protected]/thread/7YMZ6DDZVR26TJJBVO3RDNBAVGHNYAKR/",
      "source": "[email protected]"
    }
  ]
}