HTTP ServerWeb server / proxy · Apache
CVE-2026-44631
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 · uneditedBuffer Underwrite vulnerability in Apache HTTP Server on crafted regular expressions in the configuration. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.
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 confidenceA buffer underwrite vulnerability exists in Apache HTTP Server versions 2.4.0-2.4.67 when processing crafted regular expressions in the configuration. This memory safety flaw allows writing before the buffer start and can be triggered remotely, potentially leading to code execution or denial of service.
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
>= 2.4.0, < 2.4.68CVSS 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
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 checksWork through these to decide whether this CVE applies to you.
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Check Apache HTTP Server installation and versionRun 'httpd -v' or 'apache2 -v' to display the server versionAffected if Version is 2.4.0 or higher but lower than 2.4.68
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Identify Apache configuration file locationsCheck 'ServerRoot' directive in httpd.conf or use 'httpd -V' to find default config paths (commonly /etc/httpd/ or /etc/apache2/)Affected if Configuration files exist in standard locations and server version is vulnerable
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Review configuration files for regex patternsSearch config files (*.conf, .htaccess) for regex-related directives like RewriteCond, RewriteRule with complex patterns, Regex with complex patterns in mod_rewrite, mod_include, or custom modulesAffected if Custom or complex regular expression patterns are defined in server configuration files
The environment is affected if Apache HTTP Server version is 2.4.0 or higher but lower than 2.4.68, and the server processes custom regular expressions in its configuration files.
Generated from the published advisory. Verify against your own configuration.
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 · scoped2.4.68
Upgrade Apache HTTP Server to version 2.4.68 or later to remediate this vulnerability. This is a critical-severity issue (CVSS 9.8) requiring immediate attention in production environments.
2.4.68
- 1. Back up the current Apache HTTP Server configuration files (httpd.conf, any included config files) and modules.
- 2. Download Apache HTTP Server version 2.4.68 from the official Apache download site (httpd.apache.org).
- 3. Stop the running Apache HTTP Server service.
- 4. Install or compile Apache HTTP Server 2.4.68, replacing the existing installation.
- 5. Restore the backed-up configuration files to the new installation.
- 6. Start the Apache HTTP Server service.
- 7. Verify the server is running the fixed version by checking 'httpd -v' or 'apachectl -V' output.
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
- Implementation4.0 h
- Testing8.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,216.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-44631 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-44631 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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