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

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

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
Facebook	WhatsApp Desktop	0.3.9309, unspecified

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2022-05-23. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-01-21T20:30:15.000Z
• Last modified: 2025-10-21T23:35:53.174Z
• Added to CISA KEV: 2022-05-23
• BOD 22-01 due: 2022-06-13

09References

• www.facebook.com — https://www.facebook.com/security/advisories/cve-2019-18426
• packetstormsecurity.com — http://packetstormsecurity.com/files/157097/WhatsApp-Desktop-0.3.9308-Cross-Site…