Security researcher vsemozhetbyt reported that when the DOMParser is used to parse text/html data in a Firefox extension, linked resources within this HTML data will be loaded. If the data being parsed in the extension is untrusted, it could lead to information leakage and can potentially be combined with other attacks to become exploitable. Reference: http://www.mozilla.org/security/announce/2012/mfsa2012-68.html Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Mozilla security researcher vsemozhetbyt as the original reporter of this flaw. Statement: This issue does not affect the version of Firefox and Thunderbird package, as shipped with Red Hat Enterprise Linux 5 and 6.