Mozilla released an emergency update for Firefox 23 on August 16, 2013. Firefox 23.0.1 addressed these issues:

• Rendering glitches on H.264 video only in FF23 on Vista (Bug 901944)
• Spellchecking broken with non-ASCII characters in profile path (Bug 902532)
• Audio static/”burble”/breakup in Firefox to Firefox WebRTC calls (Bug 901527)

Depending on the operating system and update settings (Tools > Options… > Advanced > Update Tab), users will be prompted to update within in the next 48-hours. Windows users can also go to Help > About Firefox and click the Check for Updates button. Users may also manually download and install Firefox via getfirefox.com. The next scheduled releases will be Firefox 24.0 on September 17, 2013.