# CVE-2026-19660: Divi Membership <= 2.3.0 - Unauthenticated Authentication Bypass via 'paypal_param' Parameter

> Unauthenticated attackers can log in as any user, including administrators, by manipulating a PayPal callback parameter, leading to full site takeover.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Oct 2026
- **Updated:** 3 Oct 2026
- **Also known as:** GHSA-fwjj-2936-g23h

## What is CVE-2026-19660?

CVE-2026-19660 is a critical authentication bypass vulnerability in DiviEngine Divi Membership, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Divi Membership plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 2.3.0. The `process_paypal_callback` function, hooked to the `init` action, accepts a base64-encoded `paypal_param` GET parameter with no IPN validation, no cryptographic signature check, no ownership verification, and no nonce, allowing it to trust an entirely attacker-controlled user ID value that is passed directly to `wp_set_current_user()` and `wp_set_auth_cookie()`. This makes it possible for unauthenticated attackers to log in as any existing WordPress user — including administrators — by supplying an arbitrary user ID in the `paypal_param` GET parameter, resulting in full site takeover. The vulnerability is further compounded by the fact that the PayPal gateway class is instantiated unconditionally regardless of whether PayPal is enabled or configured, ensuring the vulnerable hook is always registered on every front-end request.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-19660?


## How do I fix CVE-2026-19660?

No fix has been published for CVE-2026-19660 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-19660 being exploited?

There is no known exploitation of CVE-2026-19660 in the wild and no public exploit code.

Public exploit code:

- Proof-of-concept scanner and exploit helper for CVE-2026-14378: unauthenticated administrator session takeover in the WordPress plugin DevKit Pro (dplugins) through a flawed user-switch “revert” flow. (github_poc): https://github.com/MRdark-ops/CVE-2026-19660-exploit
- Divi Membership (DiviEngine) pre-auth admin takeover — CVE-2026-19660 paypal_param bypass. Python PoC with exploit + cookie export. (github_poc): https://github.com/murrez/CVE-2026-19660

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-19660 and fix it if it is affected.

What it is: CVE-2026-19660 is a critical authentication bypass vulnerability in DiviEngine Divi Membership, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-19660 in the wild and no public exploit code.

Affected product: DiviEngine Divi Membership. 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-2026-19660/ (Markdown: https://insights.sbomify.com/CVE-2026-19660/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-19660
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19660
- OSV: https://osv.dev/vulnerability/CVE-2026-19660

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-19660/
Summaries are generated and may contain mistakes; the official description above is the record.