CVE-2026-53904 MCO Password Reset Denial of Service Vulnerability
MCO is vulnerable to Account Denial of Service due to improper implementation of password reset functionality. Each password reset request invalidates previously set password as well as previously issued temporary passwords, furthermore, password resets are not limited in any way. An attacker who provides victim's email and answer to their security question, can successfully initiate the reset process and continuously invalidate credentials, effectively locking the victim out of their account. Answering security questions has a limited number of tries which lowers the risk of this vulnerability. Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
Quick answer
MyComplianceOffice MCO should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- 25.3.3.1
Fixed versions
- No vendor fix published yet
How to fix it
MCO is affected and there is no public fixed version listed in the local advisory data yet. Reduce access, disable risky features where possible, and apply the vendor fix when it is released.
- Check where MCO is installed and whether it is reachable from the internet.
- Limit access to trusted users, trusted networks, or a VPN until a vendor fix is available.
- Disable the affected feature if the advisory points to a specific upload, login, reset, or document workflow.
- Watch the vendor or advisory source and apply the first supported fix as soon as it is released.
- Review logs for strange access, failed attempts, file uploads, or unexpected account activity.
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Verify the fix
- Confirm the installed version is no longer in the affected range.
- Retest the affected page, API, upload, login, or document flow.
- Check logs after the change for blocked attempts or errors.
- Run a fresh Fixnx scan and save the report.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-53904?
MyComplianceOffice MCO versions listed as affected should be reviewed: 25.3.3.1.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.