CVE-2025-11721

Memory safety bug present in Firefox 143 and Thunderbird 143. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 144 and Thunderbird 144.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1986816	Issue Tracking Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-81/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-84/	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox::::::::
	cpe:2.3:a:mozilla:thunderbird::::::::

History

18 Oct 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) Error de seguridad de memoria presente en Firefox 143 y Thunderbird 143. Este error mostró evidencia de corrupción de memoria y presumimos que con suficiente esfuerzo esto podría haber sido explotado para ejecutar código arbitrario. Esta vulnerabilidad afecta a Firefox < 144 y Thunderbird < 144.

Information

Published : 2025-10-14 13:15

Updated : 2026-10-18 21:10

NVD link : CVE-2025-11721

Mitre link : CVE-2025-11721

CVE.ORG link : CVE-2025-11721

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer

{"id": "CVE-2025-11721", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-11721", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2025-10-18T03:55:48.060426Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@mozilla.org", "affectedData": [{"vendor": "Mozilla", "product": "Firefox", "versions": [{"status": "unaffected", "version": "144", "versionType": "rpm", "lessThanOrEqual": "*"}]}, {"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "unaffected", "version": "144", "versionType": "rpm", "lessThanOrEqual": "*"}]}]}], "published": "2025-10-14T13:15:38.520", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1986816", "tags": ["Issue Tracking", "Permissions Required"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2025-81/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2025-84/", "tags": ["Vendor Advisory"], "source": "security@mozilla.org"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-119"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-119"}]}], "descriptions": [{"lang": "en", "value": "Memory safety bug present in Firefox 143 and Thunderbird 143. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 144 and Thunderbird 144."}, {"lang": "es", "value": "Error de seguridad de memoria presente en Firefox 143 y Thunderbird 143. Este error mostr\u00f3 evidencia de corrupci\u00f3n de memoria y presumimos que con suficiente esfuerzo esto podr\u00eda haber sido explotado para ejecutar c\u00f3digo arbitrario. Esta vulnerabilidad afecta a Firefox < 144 y Thunderbird < 144."}], "lastModified": "2026-10-18T21:10:00.120", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4B82B1C7-1B0F-45B7-8234-D85DDEB63886", "versionEndExcluding": "144.0", "versionStartIncluding": "143.0"}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "08E54DCC-0AA4-47DE-9DF2-C4135B0D433D", "versionEndExcluding": "144.0", "versionStartIncluding": "143.0"}], "operator": "OR"}]}], "sourceIdentifier": "security@mozilla.org"}