HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. May 4, 2026 · NIST NVD

   Detected

   HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers. This issue affects Apache HTTP Server: from through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

2. Jun 17, 2026 · NIST NVD

   Updated

   HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers. This issue affects Apache HTTP Server: from through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Affected

• cpe apache/http serverversion unspecified

Sources

• CVE.orgVulnerability recordCVE-2026-33523

  Official CVE identifier

  cve.org
• NIST NVDVulnerability recordCVE-2026-33523

  HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers. This issue affects Apache HTTP Server: from through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

  nvd.nist.gov

References

• Mailing List · openwall.com
• Vendor Advisory · httpd.apache.org