What’s Vulnerable › Vulnerabilities

CVE-2025-23048: Apache HTTP Server: mod_ssl access control bypass with session resumption

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-07-10 · updated 2026-06-17
• Weakness: CWE-284

Description

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption. Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.

Affected products

• Apache HTTP Server: from 2.4.35 before 2.4.64 — fixed in 2.4.64

How to fix

Upgrade to a fixed version: Apache HTTP Server 2.4.64. Check the vendor advisory for mitigations.

References

• https://httpd.apache.org/security/vulnerabilities_24.html
• http://www.openwall.com/lists/oss-security/2025/07/10/2
• http://www.openwall.com/lists/oss-security/2025/07/10/8
• https://lists.debian.org/debian-lts-announce/2025/08/msg00009.html

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