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CVE-2026-109763

Full vulnerability record from the local CVENow database.

Description

Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

Severity
MEDIUM
CVSS score
5.4 (v3.1)
Vulnerability status
Deferred
Source identifier
Published
2026-10-13 13:17:27.150000
Last modified
2026-10-30 20:16:58.823000
View original CVE JSON
{
  "id": "CVE-2026-109763",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-13T13:17:27.150",
  "lastModified": "2026-10-30T20:16:58.823",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Mozilla",
          "product": "Firefox",
          "versions": [
            {
              "version": "153.5",
              "lessThanOrEqual": "153.*",
              "versionType": "rpm",
              "status": "unaffected"
            },
            {
              "version": "158",
              "lessThanOrEqual": "*",
              "versionType": "rpm",
              "status": "unaffected"
            }
          ]
        },
        {
          "vendor": "Mozilla",
          "product": "Thunderbird",
          "versions": [
            {
              "version": "153.5",
              "lessThanOrEqual": "153.*",
              "versionType": "rpm",
              "status": "unaffected"
            },
            {
              "version": "158",
              "lessThanOrEqual": "*",
              "versionType": "rpm",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.5
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-19T19:28:33.740608Z",
          "id": "CVE-2026-109763",
          "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-20"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2072501",
      "source": "[email protected]"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-106/",
      "source": "[email protected]"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-108/",
      "source": "[email protected]"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-109/",
      "source": "[email protected]"
    },
    {
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-110/",
      "source": "[email protected]"
    }
  ]
}