When NGINX Plus is configured to use the Message Queuing Telemetry Transport (MQTT) filter module (ngxstreammqttfiltermodule), unauthenticated attackers can send requests with conditions beyond the attacker's control to cause a heap buffer over-read in the NGINX worker process, leading to a restart.
When NGINX Plus is configured to use the Message Queuing Telemetry Transport (MQTT) filter module (ngxstreammqttfiltermodule), unauthenticated attackers can send requests with conditions beyond the attacker's control to cause a heap buffer over-read in the NGINX worker process, leading to a restart.
A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. 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.
A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. 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.
Last updated 20 July 2026
NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpssimodule module. This vulnerability may exist when the Server-Side Includes (SSI), proxypass, and proxybuffering off directives are configured. With this configuration, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to cause a use-after-free in the NGINX worker process. This issue may lead to limited modification of memory or a restart of the NGINX worker process.