Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform: authentication bypass
Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform
Authentication bypass in the Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform component. Threat level: Critical (CVSS 9.8).
Who is affected
This vulnerability affects: Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform. If you use this component on your site, check the version and update it as soon as possible.
How dangerous
Rating: Critical, CVSS 9.8 out of 10. Critical flaws are often exploited en masse within hours of disclosure.
What this flaw is
Authentication bypass lets an attacker gain access or privileges without knowing the password, by exploiting a flaw in the login mechanism.
The attacker enters the panel like a normal administrator, without the usual signs of a breach, which makes it hard to detect.
Score breakdown (CVSS vector)
What the CVSS 9.8 rating means in practice:
- The attack can be carried out remotely, over the internet.
- No login or account required.
- Requires no action from the victim.
- At risk: data confidentiality, integrity (data can be altered), site availability.
Weakness class: CWE-287.
How to fix: authentication bypass
- Update the login/authentication component to the fixed version as a priority.
- Force a password reset for all users and invalidate active sessions.
- Enable two-factor authentication for administrator accounts.
- Review the user list and remove any accounts you do not recognise.
Prefer not to do this yourself? We will handle the update, check for signs of a break-in and secure the site. Write to us →
Frequently asked questions
Does this vulnerability affect my site?
It affects sites that use Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform. Check whether you have this component installed and which version, the flaw only applies to the vulnerable version range. You can verify it in under a minute with our free vulnerability scanner.
How do I check whether I have the vulnerable version?
In your admin panel (in WordPress: Plugins / Themes) check the installed version of Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform and compare it with the vendor advisory that names the fixed version. If it is lower, or you are not sure, run our scanner, which reads the versions visible in the site code.
How urgently should I react?
This is a Krytyczna-severity flaw, so treat it as urgent, high-impact vulnerabilities are often exploited automatically within hours of disclosure. Update as soon as possible.
What if a patch is not available yet?
Until a fix ships, reduce the exposure: temporarily disable the vulnerable component, restrict access to the affected functionality, or add a WAF rule blocking the vulnerable request. Keep a current off-site backup and watch for signs of a break-in.
Is updating alone enough?
If the site has not been attacked yet, updating to the patched version closes the hole. If there are already signs of compromise (unknown files, new admin accounts, redirects), the update does not undo the break-in, you also need to clean the site and rotate passwords and the WordPress salts.
Does this flaw affect your site?
We will run a free audit: we check versions, plugins, and configuration, and tell you plainly whether you are safe.
Request a free audit →