CVE-2026-15176 NGINX ngx_http_core_module vulnerability

Critical 9.2 Published Updated

Remote attackers can cause denial of service or potentially execute code via heap buffer overflow in NGINX when specific alias and rewrite configurations are used.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-15176?

CVE-2026-15176 is a critical memory corruption vulnerability in F5 NGINX Open Source, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability exists in NGINX Plus and NGINX Open Source when a location is configured that uses the alias directive together with rewrite and a set or return directive referencing the $request_filename variable. Alternatively, the same result could be achieved when the $request_filename variable is used in an access log format directive. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.

Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-122

Which versions are affected by CVE-2026-15176?

2 open source packages ship an affected version, including nginx and nginx-gateway.

PackageAffectedFixed in
nginx BitnamiFrom 0.1.291.30.6, 1.31.7
nginx-gateway BitnamiFrom 0.1.291.30.6, 1.31.7

How do I fix CVE-2026-15176?

Upgrade nginx to a fixed version for your release line: 1.30.6 or 1.31.7.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-15176 being exploited?

There is no known exploitation of CVE-2026-15176 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Sources

Also known as ALPINE-CVE-2026-15176, AZL-108446, BELL-CVE-2026-15176, BIT-nginx-2026-15176, BIT-nginx-gateway-2026-15176, CLSA-2026-1792146840 and 15 more.

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