CVE-2026-56154 Apache HTTP Server: mod_rewrite use-after-free via %{LA-U:HTTP:...}
Attackers can trigger a use-after-free in Apache mod_rewrite via lookahead directives, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-56154?
CVE-2026-56154 is a critical use after free vulnerability in Apache Http Server, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2026-56154?
1 open source package ship an affected version, including apache. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
apache Bitnami | From 2.4.0 | 2.4.69 |
Products include Apache Http Server.
How do I fix CVE-2026-56154?
Upgrade apache to 2.4.69 or later.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-56154 being exploited?
There is no known exploitation of CVE-2026-56154 in the wild and no public exploit code.
Other vulnerabilities in Apache Http Server
Sources
Also known as ALPINE-CVE-2026-56154, AZL-106764, BELL-CVE-2026-56154, BIT-apache-2026-56154, CLSA-2026-1791395988, CLSA-2026-1791396324 and 6 more.