{"id":"CVE-2019-18426","published":"2020-01-21T21:15:16Z","modified":"2026-06-17T02:25:01Z","title":"WhatsApp Cross-Site Scripting Vulnerability","vendor":"Meta Platforms","product":"WhatsApp","tier":"core","eol":null,"description":{"text":"A vulnerability in WhatsApp Desktop versions prior to 0.3.9309 when paired with WhatsApp for iPhone versions prior to 2.20.10 allows cross-site scripting and local file reading. Exploiting the vulnerability requires the victim to click a link preview from a specially crafted text message.","provenance":"source","from":"NVD"},"summary":{"text":"A cross-site scripting flaw in WhatsApp Desktop, prior to 0.3.9309 when paired with WhatsApp for iPhone prior to 2.20.10, stems from improper neutralization of input during web page generation. An attacker can use it to run script and read local files, but only by sending a specially crafted text message that the victim must interact with by clicking a link preview.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:54:03Z"},"cvss":{"score":8.2,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.67859,"percentile":0.99317,"date":"2026-10-28","provenance":"source"},"kev":{"dateAdded":"2022-05-23","dueDate":"2022-06-13","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2019-18426","provenance":"source"},"vulncheckKev":{"dateAdded":"2022-04-12","exploitedFirstSeen":"2022-04-12","ransomware":true,"evidence":[{"url":"https://cybersecurityworks.com/howdymanage/uploads/file/RansomwareUpdate%20Report%202022%20Q1.pdf","date":"2022-04-12"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2022-05-23"}],"evidenceTotal":2,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"references":[{"url":"http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site-Scripting.html","tags":["Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://www.facebook.com/security/advisories/cve-2019-18426","tags":["Vendor Advisory"]},{"url":"http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site-Scripting.html","tags":["Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://www.facebook.com/security/advisories/cve-2019-18426","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-18426","tags":["US Government Resource"]}],"techniques":[{"id":"T1204.001","name":"Malicious Link","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: victim clicks crafted link preview","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"Exploiting the vulnerability requires the victim to click a link preview","start":178,"end":250}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1005","name":"Data from Local System","tactics":["collection"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: local file reading yields data","mappingType":"primary_impact","evidence":[{"from":"description","quote":"allows cross-site scripting and local file reading","start":126,"end":176}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059.007","name":"JavaScript","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: XSS executes script in desktop client","mappingType":"primary_impact","evidence":[{"from":"description","quote":"allows cross-site scripting and local file reading","start":126,"end":176}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2019-8195","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-8195","exploited":true,"exploitedSince":"2022-05-23","provenance":"source"},"exploits":[{"id":48295,"url":"https://www.exploit-db.com/exploits/48295","title":"WhatsApp Desktop 0.3.9308 - Persistent Cross-Site Scripting","type":"webapps","platform":"multiple","date":"2020-04-06","verified":false,"provenance":"source"}],"exploitSources":{"exploitdb":{"count":1,"earliest":"2020-04-06"},"pocGithub":{"count":1,"skipped":0,"earliest":"2020-02-29","earliestUrl":"https://github.com/HumanSecurity/CVE-2019-18426","repos":[{"name":"HumanSecurity/CVE-2019-18426","url":"https://github.com/HumanSecurity/CVE-2019-18426","stars":11,"created":"2020-02-29"}]},"first":{"date":"2020-02-29","source":"PoC-in-GitHub","url":"https://github.com/HumanSecurity/CVE-2019-18426"},"provenance":"source"},"exploitRefs":["http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site-Scripting.html"],"flow":[{"stage":"exploitation","techniques":["T1204.001"],"provenance":"ai"},{"stage":"primary","techniques":["T1059.007","T1005"],"provenance":"ai"}],"timeline":[{"date":"2020-01-21","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2019-18426","provenance":"source"},{"date":"2020-02-29","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub; later: Exploit-DB 2020-04-06","url":"https://github.com/HumanSecurity/CVE-2019-18426","provenance":"source"},{"date":"2022-04-12","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://cybersecurityworks.com/howdymanage/uploads/file/RansomwareUpdate%20Report%202022%20Q1.pdf","provenance":"source"},{"date":"2022-05-23","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2022-05-23","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-8195","provenance":"source"}],"speed":{"daysToPublicExploit":39,"firstExploitFrom":"PoC-in-GitHub","daysToKev":853},"priority":{"score":78.6,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 1661 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":19.86,"detail":"percentile 0.9932"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit; 1 Exploit-DB entry; 1 PoC-in-GitHub repo"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.74,"detail":"base score 8.2"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}