CVE-2019-18426: WhatsApp Cross-Site Scripting Vulnerability

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: yes — in CISA KEV since 2022-05-23
EPSS: 67.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-01-21 · updated 2026-06-17
Weakness: CWE-79

Description

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.

Affected products

Facebook WhatsApp for Android: before 0.3.9309; before 2.20.10 — fixed in 0.3.9309, 2.20.10

How to fix

Upgrade to a fixed version: Facebook WhatsApp for Android 0.3.9309, 2.20.10. Check the vendor advisory for mitigations.

References

http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site-Scripting.html
https://www.facebook.com/security/advisories/cve-2019-18426
http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site-Scripting.html
https://www.facebook.com/security/advisories/cve-2019-18426
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-18426

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