USN-626-1 fixed vulnerabilities in xulrunner-1.9. The changes required that Devhelp, Epiphany, Midbrowser and Yelp also be updated to use the new xulrunner-1.9.
Original advisory details:
A flaw was discovered in the browser engine. A variable could be made to overflow causing the browser to crash. If a user were tricked into opening a malicious web page, an attacker could cause a denial of service or possibly execute arbitrary code with the privileges of the user invoking the program. (CVE-2008-2785)
Billy Rios discovered that Firefox and xulrunner, as used by browsers such as Epiphany, did not properly perform URI splitting with pipe symbols when passed a command-line URI. If Firefox or xulrunner were passed a malicious URL, an attacker may be able to execute local content with chrome privileges. (CVE-2008-2933)