WordPress Multiple Vulnerabilities

Multiple vulnerabilities have been identified in WordPress, which can be exploited by malicious people to conduct cross-site scripting and bypass certain security restrictions.

1. An error in the cookie keyed hash value verification can be exploited to gain unauthorized access.
2. An error when verifying the "publish_post" capability can be exploited to perform otherwise restricted operations e.g. publish new post with the Contributor role.
3. Certain unspecified input related to Plupload is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.