dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2025-23048

CRITICAL · 9.1 CVSS v3.1 Published 2025-07-10
Fix available
A fix is available. Upgrade to 2.4.64 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In affected Apache HTTP Server versions (2.4.35-2.4.63) with mod_ssl, when multiple virtual hosts are configured with different client certificate authorities (SSLCACertificateFile/Path), TLS 1.3 session resumption can allow a client certificate trusted for one vhost to be reused when connecting to another vhost, bypassing the intended access controls when SSLStrictSNIVHostCheck is disabled.

MitigationEnable SSLStrictSNIVHostCheck on all affected virtual hosts using client certificate authentication, or apply the vendor patch when released.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
HTTP ServerWeb server / proxy
Affected:>= 2.4.35, < 2.4.64

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Apache HTTP Server version
    Run 'httpd -v' or 'apache2 -v' to get the installed version number
    Affected if Version is 2.4.35 through 2.4.63 (inclusive)
  2. Verify mod_ssl is loaded
    Check for 'mod_ssl' in the output of 'httpd -M' or 'apache2ctl -M', or look for 'LoadModule ssl_module' in the configuration
    Affected if mod_ssl module is loaded and SSL virtual host configurations exist
  3. Identify multiple vhosts with client CA configuration
    Search configuration files (httpd.conf, ssl.conf, or included vhost files) for 'SSLCACertificateFile' or 'SSLCACertificatePath' directives appearing in multiple <VirtualHost> blocks with different certificate authority paths
    Affected if Two or more virtual hosts are configured with different SSLCACertificateFile or SSLCACertificatePath values
  4. Check SSLStrictSNIVHostCheck setting
    Search configuration for 'SSLStrictSNIVHostCheck' directive and verify its value in each affected virtual host
    Affected if SSLStrictSNIVHostCheck is set to 'off' or not explicitly set (defaults to off) in virtual hosts using client certificate authentication

User is affected if running Apache 2.4.35-2.4.63, has mod_ssl loaded, has multiple vhosts with different client certificate authorities configured, and SSLStrictSNIVHostCheck is disabled or not set.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.4.64 or later
Fixed in 2.4.64
Interim mitigation

Enable SSLStrictSNIVHostCheck on all affected virtual hosts using client certificate authentication, or apply the vendor patch when released.

Recommended fix High confidence

2.4.64

  1. Upgrade Apache HTTP Server to version 2.4.64 or later to resolve the TLS 1.3 session resumption access control bypass vulnerability

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in HTTP Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing6.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,320
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,312.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-23048 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-23048 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data