dbcve.org
Improper Signature VerificationWeakness · CWE-347

CVE-2026-9027

MEDIUM · 5.3 CVSS v3.1 Published 2026-07-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The CorvusPay WooCommerce Payment Gateway plugin for WordPress is vulnerable to Payment Bypass via Improper Verification of Cryptographic Signature in all versions up to, and including, 2.7.4. The `corvuspay_success_handler` function registers the REST endpoint `POST /wp-json/corvuspay/success/` with `'permission_callback' => '__return_true'`, and while it calls `$this->client->validate->signature()` and stores the boolean result in `$res`, the result is never evaluated in a conditional — it is only written to the debug log — causing execution to unconditionally reach `$order->payment_complete()` regardless of whether the cryptographic signature is valid. This makes it possible for unauthenticated attackers to mark any pending WooCommerce order as fully paid by sending a POST request to the success endpoint containing an arbitrary or forged signature value, allowing them to obtain goods or services without payment. Because WooCommerce order IDs are sequential integers, target orders are trivially enumerable via the `order_number` POST parameter, requiring no prior knowledge of the victim order.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The CorvusPay WooCommerce Payment Gateway plugin for WordPress has a payment bypass vulnerability in versions up to 2.7.4. The REST endpoint `/wp-json/corvuspay/success/` is publicly accessible and the signature validation result is never evaluated—it is only logged—allowing unauthenticated attackers to mark any order as paid by sending a forged signature with an enumerated order number.

MitigationUpdate the plugin to a version that properly evaluates the signature validation result in a conditional before calling `$order->payment_complete()`, and add proper permission checking to the REST endpoint.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if CorvusPay plugin is installed
    In WordPress admin, go to Plugins > Installed Plugins and look for 'CorvusPay WooCommerce Payment Gateway' or check the file system for the plugin directory at wp-content/plugins/corvuspay-woocommerce-payment-gateway
    Affected if The plugin is installed and active
  2. Check the installed plugin version
    In WordPress admin Plugins list, find CorvusPay and note the version number displayed, or check the main plugin file (e.g., corvuspay-woocommerce-payment-gateway.php) for the 'Version' header comment
    Affected if Version is 2.7.4 or lower (any version up to and including 2.7.4)
  3. Verify the vulnerable REST endpoint exists and is accessible
    Send a GET request to /wp-json/corvuspay/success/ on the site (no authentication required). If the endpoint responds with a valid JSON structure (even if showing an error), the endpoint is exposed
    Affected if The endpoint returns any JSON response (vulnerable endpoint is exposed)
  4. Inspect signature validation logic in the success handler
    Examine the PHP file handling the /success/ endpoint (typically in includes/class-corvuspay-gateway.php or similar). Look for the code handling the signature parameter - check if the validation result (often stored in a variable like $signature_valid or $is_valid) is used in a conditional (if statement) before calling payment_complete()
    Affected if The signature validation result is logged but NOT used in a conditional before payment_complete() - the result is only written to logs without being evaluated

If the CorvusPay plugin version is 2.7.4 or lower AND the /wp-json/corvuspay/success/ endpoint is accessible AND the signature validation result is only logged without being evaluated in code, the site is affected by this payment bypass vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update the plugin to a version that properly evaluates the signature validation result in a conditional before calling `$order->payment_complete()`, and add proper permission checking to the REST endpoint.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-9027 in production — separate from our analysis above.

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What this is

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