Apache HTTP Server: Heap Underflow in `ap_regname` via Signed Char Overflow
CVE-2026-44631

9.8CRITICAL

Key Information:

Vendor

Apache
Status
Apache Http Server
Vendor
CVE Published:
8 June 2026

What is CVE-2026-44631?

Buffer Underwrite vulnerability in Apache HTTP Server on crafted regular expressions in the configuration.

This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67.

Users are recommended to upgrade to version 2.4.68, which fixes the issue.

Affected Version(s)

Apache HTTP Server 2.4.0 <= 2.4.67

References

https://httpd.apache.org/security/vulnerabilities_24.html
vendor-advisory

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Zhenpeng (Leo) Lin at depthfirst
Bartlomiej Dmitruk
.