CVE-2025-23419
Summary
When multiple server blocks are configured to share the same IP address and port, an attacker can use session resumption to bypass client certificate authentication requirements on these servers. This vulnerability arises when TLS Session Tickets https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key are used and/or the SSL session cache https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache are used in the default server and the default server is performing client certificate authentication. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Impact & exploitability
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.