Severity: low Affected versions:
- Apache HTTP Server 2.4.0 through 2.4.66 Description: 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. Credit: Haruki Oyama (Waseda University) (finder) Merih Mengisteab (finder) Dawit Jeong (finder) References: https://httpd.apache.org/security/vulnerabilities_24.html https://httpd.apache.org/ https://www.cve.org/CVERecord?id=CVE-2026-33523 Timeline: 2026-03-05: reported 2026-05-04: 2.4.67 released 2026-05-04: fixed in 2.4.x by r1933360
