F5 NGINX Gateway Fabric up to 2.6.3 NGINX Configuration Generator injection

Summaryinfo

A vulnerability classified as critical has been found in F5 NGINX Gateway Fabric up to 2.6.3. This vulnerability affects unknown code of the component NGINX Configuration Generator. This manipulation causes injection. This vulnerability appears as CVE-2026-50107. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in F5 NGINX Gateway Fabric up to 2.6.3. Affected by this vulnerability is some unknown processing of the component NGINX Configuration Generator. The manipulation with an unknown input leads to a injection vulnerability. The CWE definition for the vulnerability is CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

When NGINX Plus or NGINX Open Source is configured as the data plane for NGINX Gateway Fabric, an injection vulnerability exists in the NGINX configuration generator component of NGINX Gateway Fabric. User-supplied string values from the NginxProxy Custom Resource Definition (CRD) access log format setting are rendered directly into NGINX configuration templates without sanitization or escaping. An authenticated attacker with permission to create or modify these CRDs may craft values that inject arbitrary NGINX configuration directives. This is a control plane issue; there is no data plane exposure from the vulnerability trigger itself. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

The advisory is shared at my.f5.com. This vulnerability is known as CVE-2026-50107 since 06/17/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/18/2026). MITRE ATT&CK project uses the attack technique T1055 for this issue.

Upgrading to version 2.6.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1995). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• NGINX NGINX
• NGINX NGINX Plus

Productinfo

Type

• Web Server

Vendor

• F5

Name

• NGINX Gateway Fabric

Version

• 2.6.0
• 2.6.1
• 2.6.2
• 2.6.3

License

• commercial

Website

• Vendor: https://f5.com/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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