telepathy-idle before 0.1.15 does not verify (1) that the issuer is a trusted CA, (2) that the server hostname matches a domain name in the subject's Common Name (CN), or (3) the expiration date of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.
AV:N/AC:M/Au:N/C:P/I:P/A:N
This vulnerability has a 0.95% probability of being exploited in the next 30 days, ranking higher than 60% of all scored CVEs.