REDHAT-BUG-2500992: High severity Nginx NGINX Plus vulnerability

Published Jul 15, 2026

Updated

NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpslicemodule module. When the slice directive and unnamed regex captures are configured or when a background cache update happens, unauthenticated attackers can send requests that may cause uninitialized memory access in the NGINX worker process, leading to limited disclosure of memory or a restart.

Impact: This vulnerability may allow remote, unauthenticated attackers to have limited control to disclose memory contents or restart the NGINX worker process. There is no control plane exposure; this is a data plane issue only. Note: The ngxhttpslicemodule module is not enabled by default; it's enabled with the --with-httpslicemodule configuration parameter.

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

Affected Software

2 affected components

Nginx NGINX Plus

Nginx NGINX Open Source

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Compensating control
If the ngx_http_slice_module is not required, do not enable it (do not configure NGINX with the --with-http_slice_module parameter), since it is disabled by default.

Event History

Jul 15, 2026

Data Sourced

via Red Hat·04:01 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which deployments are exposed to this issue?

Only data-plane NGINX deployments using ngx_http_slice_module are implicated. The module is not enabled by default; it must have been built with the --with-http_slice_module configuration parameter.

What conditions can trigger the vulnerable behavior?

The issue can occur when the slice directive is used with unnamed regex captures, or when a background cache update occurs. An unauthenticated remote attacker can send requests that trigger uninitialized memory access in an NGINX worker process.

What is the expected impact of successful exploitation?

An attacker may obtain limited disclosure of memory contents or cause an NGINX worker process restart. The issue does not expose the control plane.

REDHAT-BUG-2500992: High severity Nginx NGINX Plus vulnerability

Affected Software

Remediation

Event History

Frequently Asked Questions

Which deployments are exposed to this issue?

What conditions can trigger the vulnerable behavior?

What is the expected impact of successful exploitation?

Company

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Frequently Asked Questions

Which deployments are exposed to this issue?

What conditions can trigger the vulnerable behavior?

What is the expected impact of successful exploitation?