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

> An attacker can execute scripts and read local files by tricking a WhatsApp Desktop user into clicking a malicious link preview.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Yes, since 23 May 2022 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 21 Jan 2020
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-x67c-8vp2-26mr

## What is CVE-2019-18426?

CVE-2019-18426 is a high-severity cross-site scripting vulnerability in Facebook WhatsApp Desktop, published on 21 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2019-18426?

It affects 1 product.


Products: Whatsapp Whatsapp.

## How do I fix CVE-2019-18426?

No fix has been published for CVE-2019-18426 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 13 Jun 2022.

## Is CVE-2019-18426 being exploited?

Yes. Attackers have exploited CVE-2019-18426 in the wild since at least 23 May 2022.

Public exploit code:

- https://github.com/HumanSecurity/CVE-2019-18426 (github_poc): https://github.com/HumanSecurity/CVE-2019-18426
- WhatsApp Desktop 0.3.9308 - Persistent Cross-Site Scripting (exploitdb)

## Other vulnerabilities in Facebook WhatsApp Desktop

- [CVE-2019-3568](https://insights.sbomify.com/CVE-2019-3568/): WhatsApp VOIP Stack Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2025-55177](https://insights.sbomify.com/CVE-2025-55177/): Meta Platforms WhatsApp Incorrect Authorization (medium 5.4, exploited in the wild)
- [CVE-2022-36934](https://insights.sbomify.com/CVE-2022-36934/): Integer overflow in WhatsApp Business for Android (critical 9.8)
- [CVE-2021-24042](https://insights.sbomify.com/CVE-2021-24042/): Memory corruption in WhatsApp Business for Android (critical 9.8)
- [CVE-2021-24041](https://insights.sbomify.com/CVE-2021-24041/): Memory corruption in WhatsApp Business for Android (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-18426 and fix it if it is affected.

What it is: CVE-2019-18426 is a high-severity cross-site scripting vulnerability in Facebook WhatsApp Desktop, published on 21 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: Yes. Attackers have exploited CVE-2019-18426 in the wild since at least 23 May 2022.

Affected product: Facebook WhatsApp Desktop. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2019-18426/ (Markdown: https://insights.sbomify.com/CVE-2019-18426/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18426
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18426
- OSV: https://osv.dev/vulnerability/CVE-2019-18426

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-18426/
Summaries are generated and may contain mistakes; the official description above is the record.