CVE-2026-33523
Apache HTTP Server: multiple modules: HTTP response splitting forwarding malicious status line
6.5
MEDIUM
CVSS 3.1
EPSS 0.26%
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.
How to fix CVE-2026-33523
To remediate CVE-2026-33523, upgrade the affected package to a fixed version below.
- —upgrade to 2.4.67-r0 or later
- —upgrade to 2.4.67 or later
- —upgrade to 2.4.67-1~deb11u1 or later
Is CVE-2026-33523 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 2.4.67-r0
- >= 2.4.0, < 2.4.67
- from 0, < 2.4.67-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |