CVE-2026-56154: CWE-416 Use After Free in Apache Software Foundation Apache HTTP Server
Use After Free vulnerability in Apache HTTP Server's mod_rewrite when using lookahead (%{LA-U:HTTP:...}) This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.
AI Analysis
Technical Summary
CVE-2026-56154 is a Use After Free vulnerability in the mod_rewrite component of Apache HTTP Server. It occurs specifically when using lookahead syntax (%{LA-U:HTTP:...}) in rewrite rules. The affected versions range from 2.4.0 up to and including 2.4.68. The vulnerability could lead to memory corruption due to improper handling of freed memory. No further technical details or exploit information are provided.
Potential Impact
The vulnerability could potentially allow attackers to cause memory corruption in the Apache HTTP Server process, which might lead to crashes or undefined behavior. No known exploits in the wild have been reported. The exact impact depends on how the mod_rewrite lookahead feature is used in the affected server configurations.
Mitigation Recommendations
Patch status is not yet confirmed — check the Apache Software Foundation advisory for current remediation guidance. Until a patch is available, consider avoiding the use of lookahead (%{LA-U:HTTP:...}) in mod_rewrite rules if feasible.
CVE-2026-56154: CWE-416 Use After Free in Apache Software Foundation Apache HTTP Server
Description
Use After Free vulnerability in Apache HTTP Server's mod_rewrite when using lookahead (%{LA-U:HTTP:...}) This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.
CVSS v3.1
Score 9.8critical
Affected software
Apache Software Foundation
Apache HTTP Server
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-56154 is a Use After Free vulnerability in the mod_rewrite component of Apache HTTP Server. It occurs specifically when using lookahead syntax (%{LA-U:HTTP:...}) in rewrite rules. The affected versions range from 2.4.0 up to and including 2.4.68. The vulnerability could lead to memory corruption due to improper handling of freed memory. No further technical details or exploit information are provided.
Potential Impact
The vulnerability could potentially allow attackers to cause memory corruption in the Apache HTTP Server process, which might lead to crashes or undefined behavior. No known exploits in the wild have been reported. The exact impact depends on how the mod_rewrite lookahead feature is used in the affected server configurations.
Mitigation Recommendations
Patch status is not yet confirmed — check the Apache Software Foundation advisory for current remediation guidance. Until a patch is available, consider avoiding the use of lookahead (%{LA-U:HTTP:...}) in mod_rewrite rules if feasible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-06-19T12:42:54.699Z
- State
- PUBLISHED
Threat ID: 6abe8afca43b0b3b89c7c225
Added to database: 10/01/2026, 16:31:56 UTC
Last enriched: 10/01/2026, 17:01:37 UTC
Last updated: 10/02/2026, 04:45:56 UTC
Views: 13
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