php is vulnerable to cross-site scripting (XSS). The vulnerability exists as a numeric truncation error and an input validation flaw were found in the way the PHP utf8_decode() function decoded partial multi-byte sequences for some multi-byte encodings, sending them to output without them being escaped. An attacker could use these flaws to perform a cross-site scripting attack.
bugs.php.net/bug.php?id=49687
lists.fedoraproject.org/pipermail/package-announce/2011-January/052836.html
lists.fedoraproject.org/pipermail/package-announce/2011-January/052845.html
secunia.com/advisories/42410
secunia.com/advisories/42812
sirdarckcat.blogspot.com/2009/10/couple-of-unicode-issues-on-php-and.html
www.blackhat.com/presentations/bh-usa-09/VELANAVA/BHUSA09-VelaNava-FavoriteXSS-SLIDES.pdf
www.redhat.com/security/updates/classification/#moderate
www.redhat.com/support/errata/RHSA-2010-0919.html
www.redhat.com/support/errata/RHSA-2011-0195.html
www.securityfocus.com/bid/44889
www.ubuntu.com/usn/USN-1042-1
www.vupen.com/english/advisories/2010/3081
www.vupen.com/english/advisories/2011/0020
www.vupen.com/english/advisories/2011/0021
www.vupen.com/english/advisories/2011/0077
access.redhat.com/errata/RHSA-2010:0919