{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-103500", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-09-30T17:15:06.146Z", "datePublished": "2026-09-30T17:15:06.357Z", "dateUpdated": "2026-09-30T17:19:56.134Z"}, "containers": {"cna": {"affected": [{"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.17", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "153.4", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "157", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "An attacker could cause a heap buffer overflow by getting a user to open an email that is greater than or equal to 2GB in size. This vulnerability was fixed in Thunderbird 157, Thunderbird 140.17, and Thunderbird 153.4.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "An attacker could cause a heap buffer overflow by getting a user to open an email that is greater than or equal to 2GB in size. This vulnerability was fixed in Thunderbird 157, Thunderbird 140.17, and Thunderbird 153.4."}]}], "title": "Heap buffer overflow opening large email", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2070267"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-101/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-102/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-103/"}], "credits": [{"lang": "en", "value": "Ahmed Albalawi"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-09-30T17:19:56.134Z"}}}}

{}

{"affected": [{"affectedData": [{"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.17", "versionType": "rpm"}, {"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.4", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "157", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "An attacker could cause a heap buffer overflow by getting a user to open an email that is greater than or equal to 2GB in size. This vulnerability was fixed in Thunderbird 157, Thunderbird 140.17, and Thunderbird 153.4."}], "id": "CVE-2026-103500", "lastModified": "2026-09-30T19:05:23.307", "metrics": {}, "published": "2026-09-30T18:18:18.120", "references": [{"source": "security@mozilla.org", "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2070267"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-101/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-102/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-103/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "thunderbird: thunderbird: Heap buffer overflow via opening large emails", "id": "2544154", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2544154"}, "csaw": false, "cvss3": {"cvss3_base_score": "8.8", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-787", "details": ["A flaw was found in Thunderbird. A remote attacker could exploit this vulnerability by convincing a user to open an email that is 2GB or larger, triggering a heap buffer overflow. This flaw allows an attacker to corrupt memory, which may cause an application crash, resulting in a Denial of Service (DoS), or potentially lead to arbitrary code execution."], "name": "CVE-2026-103500", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-09-30T17:15:06Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-103500\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-103500\nhttps://bugzilla.mozilla.org/show_bug.cgi?id=2070267\nhttps://www.mozilla.org/security/advisories/mfsa2026-101/"], "threat_severity": "Important"}

{"created": "2026-09-30T20:30:18.878372+00:00", "updated": "2026-09-30T20:30:18.878377+00:00", "vendors": [], "weaknesses": ["CWE-122"]}