minor #5900 Added new security advisories to the docs (fabpot)

This PR was submitted for the 2.8 branch but it was merged into the 2.3 branch instead (closes #5900).

Discussion
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Added new security advisories to the docs

Commits
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68fdb03 Added new security advisories to the docs

contributing/code/security.rst

@@ -96,6 +96,8 @@ Security Advisories
 This section indexes security vulnerabilities that were fixed in Symfony
 releases, starting from Symfony 1.0.0:
 
+* November 23, 2015: `CVE-2015-8125: Potential Remote Timing Attack Vulnerability in Security Remember-Me Service <http://symfony.com/blog/cve-2015-8125-potential-remote-timing-attack-vulnerability-in-security-remember-me-service>`_ (2.3.35, 2.6.12 and 2.7.7)
+* November 23, 2015: `CVE-2015-8124: Session Fixation in the "Remember Me" Login Feature <http://symfony.com/blog/cve-2015-8124-session-fixation-in-the-remember-me-login-feature>`_ (2.3.35, 2.6.12 and 2.7.7)
 * May 26, 2015: `CVE-2015-4050: ESI unauthorized access <https://symfony.com/blog/cve-2015-4050-esi-unauthorized-access>`_ (Symfony 2.3.29, 2.5.12 and 2.6.8)
 * April 1, 2015: `CVE-2015-2309: Unsafe methods in the Request class <https://symfony.com/blog/cve-2015-2309-unsafe-methods-in-the-request-class>`_ (Symfony 2.3.27, 2.5.11 and 2.6.6)
 * April 1, 2015: `CVE-2015-2308: Esi Code Injection <https://symfony.com/blog/cve-2015-2308-esi-code-injection>`_ (Symfony 2.3.27, 2.5.11 and 2.6.6)