CVE-2026-16377
Full vulnerability record from the local CVENow database.
Description
Mitigation bypass in the PDF Viewer component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
Severity
CRITICAL
CVSS score
9.8
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-21 13:17:12.870000
Last modified
2026-10-24 20:10:00.137000
View original CVE JSON
{
"id": "CVE-2026-16377",
"sourceIdentifier": "[email protected]",
"published": "2026-07-21T13:17:12.870",
"lastModified": "2026-10-24T20:10:00.137",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Mitigation bypass in the PDF Viewer component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13."
},
{
"lang": "es",
"value": "Omisión de mitigación en el componente Visor de PDF. Esta vulnerabilidad se corrigió en Firefox 153, Firefox ESR 140.13, Thunderbird 153 y Thunderbird 140.13."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Mozilla",
"product": "Firefox",
"versions": [
{
"version": "140.13",
"lessThanOrEqual": "140.*",
"versionType": "rpm",
"status": "unaffected"
},
{
"version": "153",
"lessThanOrEqual": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Mozilla",
"product": "Thunderbird",
"versions": [
{
"version": "140.13",
"lessThanOrEqual": "140.*",
"versionType": "rpm",
"status": "unaffected"
},
{
"version": "153",
"lessThanOrEqual": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
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"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9
}
],
"ssvcV203": [
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"id": "CVE-2026-16377",
"options": [
{
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{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
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"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
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"description": [
{
"lang": "en",
"value": "CWE-693"
}
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}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
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"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*",
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"references": [
{
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2037770",
"source": "[email protected]",
"tags": [
"Permissions Required"
]
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-68/",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-70/",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-71/",
"source": "[email protected]",
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},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2026-72/",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
}
]
}