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HTTP ServerWeb server / proxy · Apache

CVE-2026-29168

HIGH · 7.3 CVSS v3.1 Published 2026-05-05
Fix available
A fix is available. Upgrade to 2.4.67 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
Allocation of Resources Without Limits or Throttling vulnerability in Apache HTTP Server's  mod_md via OCSP response data. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.66. Users are recommended to upgrade to version 2.4.67, 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 confidence

A resource exhaustion vulnerability in Apache HTTP Server's mod_md (managed domains) module allows processing of OCSP response data without proper resource limits or throttling, potentially enabling attackers to consume excessive server resources.

MitigationUpgrade Apache HTTP Server to version 2.4.67 or later to patch the resource allocation vulnerability in mod_md's OCSP response handling.

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:>= 2.4.30, < 2.4.67

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. Determine Apache HTTP Server version
    Run 'httpd -v' or 'apache2 -v' to obtain the installed server version number
    Affected if The version is 2.4.30 or higher but below 2.4.67
  2. Verify mod_md module is loaded
    Run 'httpd -M' or 'apache2ctl -M' and search for 'mod_md' or 'md_module' in the output list of loaded modules
    Affected if mod_md appears in the loaded modules list
  3. Confirm mod_md configuration exists
    Search Apache configuration files (httpd.conf, apache2.conf, conf.d/, sites-enabled/) for 'MDomain' or 'ManagedDomain' directives, or check for 'LoadModule md_module'
    Affected if mod_md is explicitly configured with at least one managed domain directive
  4. Check OCSP stapling is enabled via mod_md
    Review Apache configuration for 'MDStaple' directive or verify that OCSP stapling is active by checking response headers with 'openssl s_client -connect localhost:443 -servername HOSTNAME -status'
    Affected if OCSP stapling is enabled and mod_md is handling certificate staple responses

A user is affected if their Apache HTTP Server version falls within 2.4.30 to 2.4.66 AND the mod_md module is loaded with managed domains configured and OCSP stapling active.

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 2.4.67 or later
Fixed in 2.4.67
Interim mitigation

Upgrade Apache HTTP Server to version 2.4.67 or later to patch the resource allocation vulnerability in mod_md's OCSP response handling.

Recommended fix High confidence

2.4.67

  1. 1. Check current Apache HTTP Server version: `apachectl -v` or `httpd -v`
  2. 2. Stop the Apache service: `sudo systemctl stop apache2` (Debian/Ubuntu) or `sudo systemctl stop httpd` (RHEL/CentOS)
  3. 3. Download Apache HTTP Server 2.4.67 from the official Apache download page (https://httpd.apache.org/download.cgi) or use your system's package manager
  4. 4. If using source compilation: Extract the tarball, run `./configure`, `make`, `sudo make install`
  5. 5. If using package manager: `sudo apt-get update && sudo apt-get install apache2` (Debian/Ubuntu) or `sudo yum update httpd` (RHEL/CentOS)
  6. 6. Verify the installed version: `apachectl -v` or `httpd -v` - confirm it shows 2.4.67
  7. 7. Start the Apache service: `sudo systemctl start apache2` (Debian/Ubuntu) or `sudo systemctl start httpd` (RHEL/CentOS)
  8. 8. Verify the service is running properly and check logs for any errors
Caveat Review mod_md configuration and test OCSP-related functionality after upgrade, as changes in mod_md may affect certificate handling

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

Fix this in HTTP Server Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

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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-2026-29168 in production — separate from our analysis above.

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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