F5 NGINX Ingress Controller up to 5.5.x Configuration Generator injection

Summaryinfo

A vulnerability classified as problematic has been found in F5 NGINX Ingress Controller up to 5.5.x. Affected by this issue is some unknown functionality of the component Configuration Generator. The manipulation leads to injection. This vulnerability is documented as CVE-2026-77180. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in F5 NGINX Ingress Controller up to 5.5.x and classified as problematic. This issue affects some unknown processing of the component Configuration Generator. The manipulation with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

When NGINX Ingress Controller is configured with Ingress annotations, an injection vulnerability exists in the configuration generator of NGINX Ingress Controller. Multiple user-controllable fields are written into the generated NGINX configuration without sanitization. An authenticated attacker with permission to create or modify these annotations may craft values that inject arbitrary NGINX configuration directives. Impact: An authenticated attacker granted write access to NGINX Ingress Controller Ingress annotations through the Kubernetes API may be able to inject arbitrary NGINX configuration directives, create or delete files, or disable services. There is no data plane exposure; this is a control plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

The advisory is shared at my.f5.com. The identification of this vulnerability is CVE-2026-77180 since 08/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation needs additional levels of successful authentication. 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 09/02/2026). MITRE ATT&CK project uses the attack technique T1055 for this issue.

Upgrading to version 5.6.0 or 2026-lts-r5 eliminates this vulnerability.

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Productinfo

Type

• Web Server

Vendor

• F5

Name

• NGINX Ingress Controller

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.5

License

• commercial

Website

• Vendor: https://f5.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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