Using the Address Sanitizer tool, security researcher Abhishek Arya (Inferno) of the Google Chrome Security Team found an out-of-bounds write when buffering WebM format video containing frames with invalid tile sizes. This can lead to a potentially exploitable crash during WebM video playback.
In general this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled, but is potentially a risk in browser or browser-like contexts.
Vulmon