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CVE-2022-34750

Status: ModifiedHigh (7.5)—

An issue was discovered in MediaWiki through 1.38.1. The lemma length of a Wikibase lexeme is currently capped at a thousand characters. Unfortunately, this length is not validated, allowing much larger lexemes to be created, which introduces various denial-of-service attack vectors within the Wikibase and WikibaseLexeme extensions. This is related to Special:NewLexeme and Special:NewProperty.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

Mediawiki — Mediawiki

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2022-34750",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2022-06-28T13:15:12.817",
  "references": [
    {
      "url": "https://gerrit.wikimedia.org/r/q/I8171bfef73e525d73efa60b407ce147130ea4742",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://gerrit.wikimedia.org/r/q/Id89a9b08e40f075d2d422cafd03668dff3ce7fc9",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://phabricator.wikimedia.org/T308659",
      "tags": [
        "Mailing List"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://gerrit.wikimedia.org/r/q/I8171bfef73e525d73efa60b407ce147130ea4742",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://gerrit.wikimedia.org/r/q/Id89a9b08e40f075d2d422cafd03668dff3ce7fc9",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://phabricator.wikimedia.org/T308659",
      "tags": [
        "Mailing List"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in MediaWiki through 1.38.1. The lemma length of a Wikibase lexeme is currently capped at a thousand characters. Unfortunately, this length is not validated, allowing much larger lexemes to be created, which introduces various denial-of-service attack vectors within the Wikibase and WikibaseLexeme extensions. This is related to Special:NewLexeme and Special:NewProperty."
    },
    {
      "lang": "es",
      "value": "Se ha detectado un problema en MediaWiki versiones hasta 1.38.1. La longitud del lema de un lexema de Wikibase está actualmente limitada a mil caracteres. Desafortunadamente, esta longitud no es comprobada, lo que permite crear lexemas mucho más grandes, lo que introduce varios vectores de ataque de denegación de servicio en las extensiones Wikibase y WikibaseLexeme. Esto está relacionado con Special:NewLexeme y Special:NewProperty"
    }
  ],
  "lastModified": "2026-06-17T04:50:51.760",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "BC979A45-0DA0-47F2-910A-3F7548950CBF",
              "versionEndIncluding": "1.38.1"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}