# CVE-2026-16650: Charitable < 1.8.12 - Unauthenticated Donation Payment-Status Manipulation via Square Webhook Signature Bypass

> Unauthenticated attackers can bypass Square webhook signature verification to forge payment notifications, marking donations as paid without actual funds.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Aug 2026
- **Updated:** 21 Aug 2026
- **Also known as:** GHSA-r6r4-9w99-4w36

## What is CVE-2026-16650?

CVE-2026-16650 is a medium-severity vulnerability in Unknown Charitable, published on 21 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Charitable WordPress plugin before 1.8.12 does not verify the authenticity of incoming Square payment webhook events in a default configuration, allowing unauthenticated attackers to forge webhook notifications that mark donations as paid without any real payment.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2026-16650?


## How do I fix CVE-2026-16650?

No fix has been published for CVE-2026-16650 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16650 being exploited?

There is no known exploitation of CVE-2026-16650 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16650 and fix it if it is affected.

What it is: CVE-2026-16650 is a medium-severity vulnerability in Unknown Charitable, published on 21 Aug 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-2026-16650 in the wild and no public exploit code.

Affected product: Unknown Charitable. 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-2026-16650/ (Markdown: https://insights.sbomify.com/CVE-2026-16650/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16650
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16650
- OSV: https://osv.dev/vulnerability/CVE-2026-16650

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16650/
Summaries are generated and may contain mistakes; the official description above is the record.