We already have new one ready and will update it on the same day @ 21:00 UTC (23:00 EET).
Affected server: api2.messente.com
Date of update: 15. November 2014 @ 21:00 UTC (23:00 EET)
New certificate: api2-messente-com.crt
If you are using https://api2.messente.com/ for making API queries (not just http://), you will need to make sure you do not cache the https certificate.
There are known issues with some Java implementations, where the certificate is cached in the keystore and needs to be manually updated. Check this forum thread on how to clear the Java certificate cache.
If you are using some other ready-made library like cURL (PHP, C++) or httplib (Python), you should be already fine. Just make sure to double-check everything on the next day