F5 Plus/Open Source ngx_http_core_module use after free

Summaryinfo

A vulnerability, which was classified as critical, was found in F5 Plus and Open Source. The impacted element is an unknown function of the component ngx_http_core_module. Executing a manipulation can lead to use after free. This vulnerability is tracked as CVE-2026-97205. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical was found in F5 Plus and Open Source (affected version not known). This vulnerability affects some unknown functionality of the component ngx_http_core_module. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_core_module module. When asynchronous file I/O (AIO) is enabled in certain configurations, processing a Server Side Includes (SSI) page containing “include virtual” commands may trigger a Use-After-Free (UAF) in the NGINX worker process. This may cause memory corruption or a worker process crash. 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, corrupt its memory, or possibly trigger 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.

The advisory is shared for download at my.f5.com. This vulnerability was named CVE-2026-97205 since 09/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 10/14/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• F5

Name

• Open Source
• Plus

License

• commercial

Website

• Vendor: https://f5.com/

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