CVE-2013-4238: The ssl.match_hostname function in the SSL module in Python 2.6 through 3.4 does not properly handle a '\0'...

Security readout for executives and security teams

Older Python SSL hostname checks could be fooled by a certificate containing a null character in a Subject Alternative Name. If an attacker could intercept traffic and had a crafted certificate issued by a trusted CA, they could impersonate SSL servers to affected Python clients. Exposure is most likely in legacy systems, appliances, or vendor products using affected Python 2.6 through 3.4 SSL hostname verification. The source bundle cites Linux distribution advisories and VMware vSphere updates, but does not provide a complete affected-product inventory. Prioritize remediation where legacy Python validates TLS for business-critical or credential-bearing connections. This is not listed as actively exploited in the supplied sources, but the potential impact is trust bypass and server impersonation. Mitigation focus: Apply relevant Python, OS, or vendor security updates from listed advisories.; Identify and retire unsupported Python 2.6 through 3.4 runtimes where possible.; Check VMware, Red Hat, Debian, Ubuntu, and openSUSE guidance for affected packages..

Prepared

Jun 14, 2026, 21:50 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.