Is CVE-2026-90977 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-90977 being exploited in the wild.

How severe is CVE-2026-90977?

Medium severity, with a CVSS score of 5.3, published 18 September 2026.

Which products and versions are affected?

Clean Login Clean Login before 1.19.

Is there a fix for CVE-2026-90977?

A patch was published on 2026-09-16: Fixed in version 1.19 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-90977 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-90977?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-90977: Clean Login WordPress plugin CAPTCHA bypass via empty session

CVE-2026-90977 · Severity: medium · CVSS 5.3 · Published 2026-09-18

Clean Login is a WordPress plugin that manages user registration and login forms. The plugin fails to validate its anti-spam CAPTCHA control when certain session values are missing, allowing attackers to automatically create fake user accounts on WordPress sites without solving the CAPTCHA challenge. This can lead to account enumeration, spam, and unauthorized access to the affected WordPress installation.

Quick answers

Is CVE-2026-90977 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-90977 being exploited in the wild.
How severe is CVE-2026-90977?: Medium severity, with a CVSS score of 5.3, published 18 September 2026.
Which products and versions are affected?: Clean Login Clean Login before 1.19.
Is there a fix for CVE-2026-90977?: A patch was published on 2026-09-16: Fixed in version 1.19 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-90977 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-90977?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a CAPTCHA bypass flaw in the Clean Login WordPress plugin's registration form validation logic. The plugin fails to verify the CAPTCHA solution when the corresponding session value is empty or missing, resulting in insufficient input validation. No authentication is required—an unauthenticated attacker can directly submit a registration request with an empty or missing session value to bypass the CAPTCHA anti-automation control. An attacker can exploit this to programmatically create multiple fake user accounts, facilitating spam, phishing, or reconnaissance attacks. The vulnerability is fixed in version 1.19 and later.

Affected products

Clean Login Clean Login before 1.19

Timeline

2026-09-16: disclosed
2026-09-16: patched: Fixed in version 1.19

References

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