---
title: "CVE-2026-56154: Apache HTTP Server - Use After Free"
description: "Apache HTTP Server 2.4.0 through 2.4.68 contains a use after free vulnerability caused by improper handling of lookahead (%{LA-U:HTTP:...}) in mod_rewrite, letting attackers cause denial of service or potentially execute code, exploit requires crafted requests."
url: https://panop.io/threat-heartbeat/CVE-2026-56154/
---

# CVE-2026-56154 Apache HTTP Server - Use After Free

Apache HTTP Server 2.4.0 through 2.4.68 contains a use after free vulnerability caused by improper handling of lookahead (%{LA-U:HTTP:...}) in mod\_rewrite, letting attackers cause denial of service or potentially execute code, exploit requires crafted requests.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.56% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-56154)

## Details

Type

Use After Free

Impact

Denial Of Service, Remote Code Execution

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

1 October 2026

Updated

15 October 2026

Weakness

[CWE-416](https://cwe.mitre.org/data/definitions/416.html)

## Vendor fix

Upgrade to a version later than 2.4.68 or the latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-56154](https://nvd.nist.gov/vuln/detail/CVE-2026-56154)
- [https://httpd.apache.org/security/vulnerabilities\_24.html](https://httpd.apache.org/security/vulnerabilities_24.html)
- [http://www.openwall.com/lists/oss-security/2026/10/01/17](http://www.openwall.com/lists/oss-security/2026/10/01/17)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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