CVE-2026-84637

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-84637", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-09-01T21:25:08.170Z", "datePublished": "2026-09-01T21:25:08.554Z", "dateUpdated": "2026-09-02T18:49:58.962Z"}, "containers": {"cna": {"affected": [{"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "153.2", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2."}]}], "title": "Calendar invitation attachments could launch local executables", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2043878"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-88/"}], "credits": [{"lang": "en", "value": "Trung Nguyen"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-09-01T21:44:14.831Z"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-434", "lang": "en", "description": "CWE-434 Unrestricted Upload of File with Dangerous Type"}]}], "metrics": [{"cvssV3_1": {"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"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-09-02T18:49:31.675786Z", "id": "CVE-2026-84637", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-02T18:49:58.962Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"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"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2026-84637", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-09-02T18:49:31.675786Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-434", "description": "CWE-434 Unrestricted Upload of File with Dangerous Type"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-02T18:49:50.938Z"}}], "cna": {"title": "Calendar invitation attachments could launch local executables", "credits": [{"lang": "en", "value": "Trung Nguyen"}], "affected": [{"vendor": "Mozilla", "product": "Thunderbird", "versions": [{"status": "unaffected", "version": "153.2", "versionType": "rpm", "lessThanOrEqual": "153.*"}, {"status": "unaffected", "version": "154", "versionType": "rpm", "lessThanOrEqual": "*"}]}], "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2043878"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-88/"}], "descriptions": [{"lang": "en", "value": "Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2.", "supportingMedia": [{"type": "text/html", "value": "Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2.", "base64": false}]}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-09-01T21:44:14.831Z"}}}, "cveMetadata": {"cveId": "CVE-2026-84637", "state": "PUBLISHED", "dateUpdated": "2026-09-02T18:49:58.962Z", "dateReserved": "2026-09-01T21:25:08.170Z", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "datePublished": "2026-09-01T21:25:08.554Z", "assignerShortName": "mozilla"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.2", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "154", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "matchCriteriaId": "42884C4B-DB1F-44A9-9238-9605B34865E5", "versionEndExcluding": "153.2.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*", "matchCriteriaId": "C6AB910B-074A-42F7-A3C7-B7E822011D92", "versionEndExcluding": "155.0", "versionStartIncluding": "154.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new invitation display enabled, the attachment could also appear under a misleading filename. This vulnerability was fixed in Thunderbird 154 and Thunderbird 153.2."}], "id": "CVE-2026-84637", "lastModified": "2026-09-03T19:02:08.287", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-84637", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-09-02T18:49:31.675786Z", "version": "2.0.3"}}]}, "published": "2026-09-01T22:17:19.597", "references": [{"source": "security@mozilla.org", "tags": ["Permissions Required"], "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2043878"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"source": "security@mozilla.org", "tags": ["Vendor Advisory"], "url": "https://www.mozilla.org/security/advisories/mfsa2026-88/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-434"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "thunderbird: Thunderbird: Arbitrary code execution via malicious calendar invitation attachments", "id": "2527103", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2527103"}, "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-59", "details": ["A flaw was found in Thunderbird. Malicious calendar invitations could use file URI attachments to launch local or network-hosted executables on Windows systems. This bypasses Thunderbird's built-in protections for executable attachments, potentially leading to arbitrary code execution. Additionally, the attachment could be disguised with a misleading filename, increasing the risk of exploitation."], "name": "CVE-2026-84637", "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": "2026-09-01T21:25:08Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-84637\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-84637\nhttps://bugzilla.mozilla.org/show_bug.cgi?id=2043878\nhttps://www.mozilla.org/security/advisories/mfsa2026-78/"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[153.2,153.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[154,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Thunderbird", "source": "cna", "vendor": "Mozilla"}, "product": "thunderbird", "vendor": "mozilla"}], "created": "2026-09-01T23:45:17.140663+00:00", "updated": "2026-09-03T16:00:08.352061+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$thunderbird"]}