{"api_version":"1","generated_at":"2026-07-23T13:25:54+00:00","cve":"CVE-2025-1942","urls":{"html":"https://cve.report/CVE-2025-1942","api":"https://cve.report/api/cve/CVE-2025-1942.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-1942","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-1942"},"summary":{"title":"Disclosure of uninitialized memory when .toUpperCase() causes string to get longer","description":"When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136.","state":"PUBLISHED","assigner":"mozilla","published_at":"2025-03-04 14:15:39","updated_at":"2026-04-13 15:16:53"},"problem_types":["CWE-908","CWE-908 CWE-908 Use of Uninitialized Resource"],"metrics":[{"version":"3.1","source":"ADP","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"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"}},{"version":"3.1","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"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"}}],"references":[{"url":"https://www.mozilla.org/security/advisories/mfsa2025-14/","name":"https://www.mozilla.org/security/advisories/mfsa2025-14/","refsource":"security@mozilla.org","tags":["Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-17/","name":"https://www.mozilla.org/security/advisories/mfsa2025-17/","refsource":"security@mozilla.org","tags":["Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1947139","name":"https://bugzilla.mozilla.org/show_bug.cgi?id=1947139","refsource":"security@mozilla.org","tags":["Issue Tracking"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-1942","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-1942","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Mozilla","product":"Firefox","version":"unaffected 136 * rpm","platforms":[]},{"source":"CNA","vendor":"Mozilla","product":"Thunderbird","version":"unaffected 136 * rpm","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"anbu","lang":"en"}],"nvd_cpes":[{"cve_year":"2025","cve_id":"1942","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"mozilla","cpe5":"firefox","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2025","cve_id":"1942","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"mozilla","cpe5":"thunderbird","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2025","cve_id":"1942","cve":"CVE-2025-1942","epss":"0.004670000","percentile":"0.644530000","score_date":"2026-04-15","updated_at":"2026-04-16 00:13:56"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"cvssV3_1":{"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"}},{"other":{"content":{"id":"CVE-2025-1942","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","timestamp":"2025-03-25T14:08:58.588635Z","version":"2.0.3"},"type":"ssvc"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-908","description":"CWE-908 Use of Uninitialized Resource","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2025-03-25T14:10:00.285Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"product":"Firefox","vendor":"Mozilla","versions":[{"lessThanOrEqual":"*","status":"unaffected","version":"136","versionType":"rpm"}]},{"product":"Thunderbird","vendor":"Mozilla","versions":[{"lessThanOrEqual":"*","status":"unaffected","version":"136","versionType":"rpm"}]}],"credits":[{"lang":"en","value":"anbu"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136."}],"value":"When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136."}],"providerMetadata":{"dateUpdated":"2026-04-13T14:30:28.192Z","orgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","shortName":"mozilla"},"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1947139"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-14/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-17/"}],"title":"Disclosure of uninitialized memory when .toUpperCase() causes string to get longer"}},"cveMetadata":{"assignerOrgId":"f16b083a-5664-49f3-a51e-8d479e5ed7fe","assignerShortName":"mozilla","cveId":"CVE-2025-1942","datePublished":"2025-03-04T13:31:25.504Z","dateReserved":"2025-03-04T12:29:51.191Z","dateUpdated":"2026-04-13T14:30:28.192Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-03-04 14:15:39","lastModifiedDate":"2026-04-13 15:16:53","problem_types":["CWE-908","CWE-908 CWE-908 Use of Uninitialized Resource"],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","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}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*","versionEndExcluding":"136.0","matchCriteriaId":"7DB4CDD0-EC54-43D0-ACB2-F159ABA53D2C"},{"vulnerable":true,"criteria":"cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*","versionEndExcluding":"136.0","matchCriteriaId":"43A02EBD-58CF-4057-A3D7-3828B599D954"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"1942","Ordinal":"1","Title":"Disclosure of uninitialized memory when .toUpperCase() causes st","CVE":"CVE-2025-1942","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"1942","Ordinal":"1","NoteData":"When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136.","Type":"Description","Title":"Disclosure of uninitialized memory when .toUpperCase() causes st"}]}}}