Vulnerabilities & Exploits

Apache Patch Hides Module-Specific Exposure Across Hosts

The real issue is not a single Apache bug. Apache HTTP Server 2.4.66 and earlier carry multiple flaws across different modules, so exposure depends on what each host actually has enabled. The most serious is a pre-authentication HTTP/2 double-free that can allow code execution.

NCSC-NL’s advisory confirms the fixed release is Apache HTTP Server 2.4.67 and lists module-specific failures in mod_proxy_ajp, mod_md, mod_dav_lock, mod_auth_digest, and mod_authn_socache, plus core-server parsing issues. The advisory also calls out .htaccess-based privilege escalation and HTTP response splitting, which broadens the blast radius beyond the headline HTTP/2 issue.

For operators, the remediation scope is the point: a binary upgrade alone does not tell you which hosts were exposed to which flaw. The fleet needs module-by-module verification because different Apache features fail in different ways, from crashes to auth bypass to code execution.

1 source · May 6

CVEs in this update

11 CVEs

Across DevOps Code ClearCase, Secure Connect Gateway, Rational ClearCase, and related packages.

0 critical · 5 high · 5 medium · 0 low

0 in CISA KEV · 0 with EPSS above 1%

Highest severity: CVE-2026-23918 · 8.8 HIGH

Highest EPSS: CVE-2026-33006 · 0.56%

Showing the top 10 by KEV, EPSS, and severity.

Timeline

Sources

Part of the PlainSec briefing for 2026-05-07

Every edition of this story: Apache Patch Hides Module-Specific Exposure Across Hosts

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