vulnerability
Apache HTTPD: TLS/SSL X.509 client certificate auth bypass with HTTP/2 (CVE-2016-4979)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:N/I:P/A:N) | Jul 6, 2016 | Jul 20, 2016 | Jul 18, 2025 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:P/A:N)
Published
Jul 6, 2016
Added
Jul 20, 2016
Modified
Jul 18, 2025
Description
The Apache HTTP Server 2.4.18 through 2.4.20, when mod_http2 and mod_ssl are enabled, does not properly recognize the "SSLVerifyClient require" directive for HTTP/2 request authorization, which allows remote attackers to bypass intended access restrictions by leveraging the ability to send multiple requests over a single connection and aborting a renegotiation.
Solution
apache-httpd-upgrade-latest
References
Rapid7 Labs
2026 Global Threat Landscape Report
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