gnutls26 - security update

Multiple vulnerabilities have been discovered in GnuTLS, a library
implementing the TLS and SSL protocols. The Common Vulnerabilities and
Exposures project identifies the following problems:

• CVE-2015-0282
  GnuTLS does not verify the RSA PKCS #1 signature algorithm to match
  the signature algorithm in the certificate, leading to a potential
  downgrade to a disallowed algorithm without detecting it.
• CVE-2015-0294
  It was reported that GnuTLS does not check whether the two signature
  algorithms match on certificate import.

For the stable distribution (wheezy), these problems have been fixed in
version 2.12.20-8+deb7u3.

We recommend that you upgrade your gnutls26 packages.