CVE intelligence

CVE-2026-33857

Vulnerability intelligence

Published May 4, 2026Sources checked Oct 27, 2026

5.3MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-33857 and is rated Medium severity with a CVSS score of 5.3. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Sep 10, 2026

USN-8571-1 fixed vulnerabilities in Apache HTTP Server.

Microsoft Security Response Center guidance

Vendor revision: Aug 10, 2026

CBL-Mariner Releases

Vendor-listed releases

2.4.67-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.4%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-33857?

Out-of-bounds Read vulnerability in mod_proxy_ajp of

Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Source: NVD