# CVE-2026-23866: Server-side request forgery in WhatsApp for Android

> Incomplete validation in WhatsApp allowed attackers to trigger media processing from arbitrary URLs, potentially invoking OS handlers on victim devices.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:F/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 May 2026
- **Updated:** 1 May 2026
- **Also known as:** GHSA-4x7f-p792-g362

## What is CVE-2026-23866?

CVE-2026-23866 is a medium-severity server-side request forgery vulnerability in Facebook WhatsApp for Android, published on 1 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Incomplete validation of AI rich response messages for Instagram Reels in WhatsApp for iOS v2.25.8.0 to v2.26.15.72 and WhatsApp for Android v2.25.8.0 to v2.26.7.10 could have allowed a user to trigger processing of media content from an arbitrary URL on another user’s device, including triggering OS-controlled custom URL scheme handlers. We have not seen evidence of exploitation in the wild.

Weakness: CWE-940 (Improper Verification of Source of a Communication Channel)

## Which versions are affected by CVE-2026-23866?

It affects 1 product.


Products: Whatsapp Whatsapp.

## How do I fix CVE-2026-23866?

No fix has been published for CVE-2026-23866 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-23866 being exploited?

There is no known exploitation of CVE-2026-23866 in the wild and no public exploit code.

## Other vulnerabilities in Facebook WhatsApp for Android

- [CVE-2019-3568](https://insights.sbomify.com/CVE-2019-3568/): WhatsApp VOIP Stack Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2019-18426](https://insights.sbomify.com/CVE-2019-18426/): WhatsApp Cross-Site Scripting (high 8.2, 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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23866 and fix it if it is affected.

What it is: CVE-2026-23866 is a medium-severity server-side request forgery vulnerability in Facebook WhatsApp for Android, published on 1 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23866 in the wild and no public exploit code.

Affected product: Facebook WhatsApp for Android. 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-2026-23866/ (Markdown: https://insights.sbomify.com/CVE-2026-23866/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23866
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23866
- OSV: https://osv.dev/vulnerability/CVE-2026-23866

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23866/
Summaries are generated and may contain mistakes; the official description above is the record.