This seems ominous:

Given the potential security implications, mSeven recommends that you immediately take steps to protect all confidential information stored within the mSecure password management application. This may include changing passwords, resetting or re-enrolling two-factor authentication methods, or removing existing passkeys.

500+ passwords, lot of changing.  This will require a triage.

 re-enrolling two-factor authentication methods? just for msecure, or every account referenced within msecure?

all passkeys that I use? 

all passkeys that I use on devices  that has msecure installed?  

just the passkey to access msecure?

If I perform these recommendations, and use the current version of msecure to manage these changes, what risks are the security implications?

Please provide more context to your email below advising there has been a security breach.
It is not acceptable to offer the vague advice "take steps".
Please state what remedial action is required, and what data was compromised. 

mSeven Software (“mSeven”) recently learned of suspicious activity associated with the mSecure password management application. In response, mSeven quickly launched an investigation, took steps to mitigate the issue, and engaged external cybersecurity experts to assist. You are receiving this email because you are a current or former mSecure customer.

Given the potential security implications, mSeven recommends that you immediately take steps to protect all confidential information stored within the mSecure password management application. This may include changing passwords, resetting or re-enrolling two-factor authentication methods, or removing existing passkeys. 

Agreed - This 'Important Security Notice' (sent to me/received on the morning of 03 Nov, 2026 at 0133mt)  is far too vague for anyone to take appropriate 'steps' to protect all confidential information stored within the mSecure password management application. You need to be far more open and explicit in regards to the level of threat and/or risk. 'Suspicious activity associated with the mSecure password management application' doesn't tell us much - Did a former employee use their (non-revoked) credentials to access a system? Are hackers currently exploiting a (now known) vulnerability? If you've taken 'steps to mitigate the issue' then why and what further steps would be necessary. With more than 800 records in my copy of mSecure, I desperately need to know what additional steps I need to take to secure the confidential information stored in mSecure!  Satisfied user/customer since 2013?

I know of two others who use Msecure, and neither of them has received this email. Is it phishing?