CVE-2026-33523: exploitation status and patch state

CVE-2026-33523 · CVSS 6.5 MEDIUM · EPSS <1% · patch available

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.

Is CVE-2026-33523 exploited?

• Not in the CISA KEV catalog.
• EPSS puts exploitation in the next 30 days at <1%.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

• CBL-Mariner Releases

What PlainSec published about CVE-2026-33523

• Debian 13.5 Refreshes Install Media, Not Your Live Fleet (2026-05-18)
• Apache Patch Hides Module-Specific Exposure Across Hosts (2026-05-07)

Primary sources

• NVD record

What this record does not say

• No affected package data.

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.