{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74936", "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "state": "PUBLISHED", "assignerShortName": "mozilla", "dateReserved": "2026-08-17T11:57:29.210Z", "datePublished": "2026-08-18T12:23:27.882Z", "dateUpdated": "2026-08-18T18:54:57.812Z"}, "containers": {"cna": {"affected": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.14", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "153.1", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"status": "unaffected", "version": "140.14", "lessThanOrEqual": "140.*", "versionType": "rpm"}, {"status": "unaffected", "version": "153.1", "lessThanOrEqual": "153.*", "versionType": "rpm"}, {"status": "unaffected", "version": "154", "lessThanOrEqual": "*", "versionType": "rpm"}]}], "descriptions": [{"lang": "en", "value": "Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1."}]}], "title": "Use-after-free in the JavaScript: WebAssembly component", "references": [{"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2052688"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-76/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-77/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-79/"}, {"url": "https://www.mozilla.org/security/advisories/mfsa2026-80/"}], "credits": [{"lang": "en", "value": "Amy Burnett of OpenAI"}], "providerMetadata": {"orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe", "shortName": "mozilla", "dateUpdated": "2026-08-18T18:54:57.812Z"}}}}

{}

{"affected": [{"affectedData": [{"product": "Firefox", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.14", "versionType": "rpm"}, {"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.1", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "154", "versionType": "rpm"}]}, {"product": "Thunderbird", "vendor": "Mozilla", "versions": [{"lessThanOrEqual": "140.*", "status": "unaffected", "version": "140.14", "versionType": "rpm"}, {"lessThanOrEqual": "153.*", "status": "unaffected", "version": "153.1", "versionType": "rpm"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "154", "versionType": "rpm"}]}], "source": "security@mozilla.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1."}], "id": "CVE-2026-74936", "lastModified": "2026-08-18T19:17:05.377", "metrics": {}, "published": "2026-08-18T13:17:29.850", "references": [{"source": "security@mozilla.org", "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2052688"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-76/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-77/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-79/"}, {"source": "security@mozilla.org", "url": "https://www.mozilla.org/security/advisories/mfsa2026-80/"}], "sourceIdentifier": "security@mozilla.org", "vulnStatus": "Undergoing Analysis"}

{"bugzilla": {"description": "firefox: thunderbird: Use-after-free in the JavaScript: WebAssembly component", "id": "2517840", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517840"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:\nUse-after-free in the JavaScript: WebAssembly component"], "name": "CVE-2026-74936", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/firefox-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/thunderbird-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"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:6", "fix_state": "Out of support scope", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"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": "firefox", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "thunderbird", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-18T12:23:27Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74936\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74936\nhttps://www.mozilla.org/security/advisories/mfsa2026-76/#CVE-2026-74936\nhttps://www.mozilla.org/security/advisories/mfsa2026-79/#CVE-2026-74936"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[140.14,140.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[153.1,153.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[154,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Firefox", "source": "cna", "vendor": "Mozilla"}, "product": "firefox", "vendor": "mozilla"}], "created": "2026-08-18T13:30:13.522667+00:00", "updated": "2026-08-18T21:15:03.489818+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox"], "weaknesses": ["CWE-416"]}