Threats / Meta Platforms / CVE-2019-18426
CVE-2019-18426
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Meta Platforms WhatsApp vulnerability
Cross-site scripting vulnerability in WhatsApp Desktop paired with WhatsApp for iPhone enables arbitrary script execution and local file access.
Verdict
Today item — known-exploited.
XSS flaw allows attackers to execute malicious scripts within WhatsApp Desktop context, potentially reading local files and compromising user data. Active exploitation observed in the wild.
CISA KEV Yes · 2022-05-235EPSS 0.67859 (verify live)6Exploit Public PoC7CVSS 8.2 (CISA)4CISA SSVC Exploitation: active · Automatable: no · Impact: partial4
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
2 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-05-23).
Probability (EPSS)
EPSS 0.67859 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 8.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N) · Affected: Meta Platforms, WhatsApp. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-79 Cross-site Scripting (XSS) — weakness family: Web / client.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: partialCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 853 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious message containing XSS payload and send it through WhatsApp.
Business
User receives message that executes attacker-controlled script in their WhatsApp Desktop application.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute JavaScript within the WhatsApp Desktop process to access local file system.
Business
Sensitive user files become accessible to the attacker without explicit user consent or awareness.
3
Lateral reach — past segmentation narrative 3
Attacker
I exfiltrate locally stored data, credentials, or conversation history from the compromised system.
Business
User privacy is breached and confidential communications are exposed to unauthorized parties.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05