CVE-2025-23419
Severity CVSS v4.0:
MEDIUM
Type:
Unavailable / Other
Publication date:
05/02/2025
Last modified:
27/01/2026
Description
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. <br />
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Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Impact
Base Score 4.0
5.30
Severity 4.0
MEDIUM
Base Score 3.x
4.30
Severity 3.x
MEDIUM
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:* | 1.11.4 (including) | 1.26.3 (excluding) |
| cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:* | 1.27.0 (including) | 1.27.4 (excluding) |
| cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* | r28 (including) | r32 (excluding) |
| cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:* | ||
| cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:* | ||
| cpe:2.3:a:f5:nginx_plus:r33:-:*:*:*:*:*:* | ||
| cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:* | ||
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |
To consult the complete list of CPE names with products and versions, see this page



