Attach image from clipboard applet has expired certificate

In YouTrack, when trying to attach an image to an issue using 'Attach file...' -> 'Image from Clipboard' feature, Java reports error about invalid certificate (see attached images). Observed both on standalone YouTrack 5.0.3 and in the sandbox http://play-sandbox.myjetbrains.com/youtrack/dashboard#newissue=yes.

Certificate in question:
Subject:
CN=JetBrains s.r.o.,
OU=SOFTWARE,
O=JetBrains s.r.o.,
L=Prague,
ST=NA,
C=CZ

Validity:
Validity    [From: Mon Oct 10 02:00:00 CEST 2011,
To: Fri Nov 08 00:59:59 CET 2013]

Java version on my machine: Version 7 Update 55
Browser: Chrome 34.0.1847.131 m
OS: Windows 7 64bit