dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2026-48913

HIGH · 7.3 CVSS v3.1 Published 2026-06-08
Fix available
A fix is available. Upgrade to 2.4.68 or later.
See remediation →
82/100
Remediation priority · High
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
Use After Free vulnerability in Apache HTTP Server module mod_http2 when file handles are already exhausted. This issue affects Apache HTTP Server: from 2.4.55 through 2.4.67.

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 · moderate confidence

A Use After Free vulnerability exists in Apache HTTP Server's mod_http2 module that is triggered when file handles are already exhausted. This memory safety issue can potentially lead to denial of service or possibly remote code execution due to accessing freed memory.

MitigationUpgrade Apache HTTP Server to version 2.4.68 or later. If immediate patching is not possible, consider limiting HTTP/2 connections or monitoring file handle usage to avoid triggering the condition.

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:>= 2.4.55, < 2.4.68

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
Low
Integrity
Low
Availability
Low

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

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 installed Apache HTTP Server version
    Run 'apache2 -v' or 'httpd -v' to obtain the server version number. On some systems, check '/usr/sbin/apache2 -v' or '/usr/sbin/httpd -v'.
    Affected if Version is >= 2.4.55 AND < 2.4.68
  2. Verify mod_http2 module is loaded
    Check the active Apache configuration for the 'mod_http2' or 'mod_h2' module. Run 'apache2ctl -M' or 'httpd -M' and look for 'http2_module' or 'h2_module' in the loaded modules list.
    Affected if mod_http2 module appears in the loaded modules list
  3. Confirm HTTP/2 protocol is enabled
    Examine Apache configuration files (typically in /etc/apache2, /etc/httpd, or the ServerRoot) for 'Protocols h2 http/1.1' or similar HTTP/2 directives. Check main config and included virtual host files.
    Affected if HTTP/2 protocol is explicitly enabled in the Apache configuration
  4. Check current file descriptor limits
    Run 'ulimit -n' to see the soft limit for open file descriptors for the Apache user. Also check system-wide limits via 'cat /proc/sys/fs/file-max' and verify the Apache process limits in the config (Directive: 'MaxConnectionsPerChild' or 'RLimitNOFILE').
    Affected if File descriptor limits are set to relatively low values (e.g., under 1024) or are exhausted in practice
  5. Count currently open file handles for Apache processes
    Run 'lsof -p $(pgrep -f apache2|head -1)' or 'ls -la /proc/$(pgrep -f apache2|head -1)/fd' to see how many files/sockets Apache is currently holding open. Compare against the configured limits.
    Affected if Apache processes are approaching or have hit the configured file descriptor limit (e.g., number of open fds equals or exceeds the ulimit -n value)

The environment is affected if Apache version is between 2.4.55 and 2.4.67 inclusive, AND mod_http2 is both loaded AND actively handling HTTP/2 connections, AND the server is operating near or at its file descriptor limits.

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 2.4.68 or later
Fixed in 2.4.68
Interim mitigation

Upgrade Apache HTTP Server to version 2.4.68 or later. If immediate patching is not possible, consider limiting HTTP/2 connections or monitoring file handle usage to avoid triggering the condition.

Recommended fix High confidence

Apache HTTP Server 2.4.68 or later

  1. 1. Identify the current Apache HTTP Server version by running 'httpd -v' or 'apache2 -v'
  2. 2. Plan a maintenance window for the upgrade (if in production environment)
  3. 3. Update your package repository and upgrade Apache HTTP Server to version 2.4.68 or later using your system's package manager (e.g., 'apt update && apt install apache2' for Debian/Ubuntu, or 'yum update httpd' for RHEL/CentOS)
  4. 4. Verify the upgrade was successful by running 'httpd -v' and confirming the version is 2.4.68 or higher
  5. 5. Restart the Apache service (e.g., 'systemctl restart apache2' or 'systemctl restart httpd')
  6. 6. Test mod_http2 functionality and ensure the server is serving requests correctly
Caveat Upgrade within the 2.4.x stable branch is typically backward compatible; however, test in a staging environment before deploying to production

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

Fix this in HTTP Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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Scan for this in your stack

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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-2026-48913 in production — separate from our analysis above.

No notes yet

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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