Add-on authors Jason Hamilton and Peter Arremann with AMO editor Sylvain Giroux reported a vulnerability when a panel is created using the Add-on SDK in a browser extension. Defining a panel with script: false is supposed to disable script execution but it was found that inline script would still execute. This flaw allows for the potential execution of script content in an extension when it was been explicitly disallowed. The potential impact of this flaw would depend on whether the add-on was relying on script: false as a security mechanism and from location the panel content was loaded. No add-ons served from addons.mozilla.org are vulnerable to this flaw but add-ons installed from third party sites may be. External Reference: https://www.mozilla.org/security/announce/2015/mfsa2015-121.html Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Jason Hamilton as the original reporter. Statement: This issue does not affect the version of firefox and thunderbird as shipped with Red Hat Enterprise Linux 5, 6 and 7.