NGINX ngxhttpcoremodule vulnerability
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 the root directive or access log format 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. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a 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.
Last updated 20 July 2026
NGINX ngxhttpproxyv2module and ngxhttpgrpcmodule vulnerability
Last updated 20 July 2026
Description When NGINX Plus or NGINX Open Source is configured with sslsessioncache
Description NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpv3module module. When using HTTP/3 with proxyrequestbuffering on directive, an unauthenticated attacker may be able to inject data in the proxied request. Impact This vulnerability may allow remote attackers to inject data in the proxied request. 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.
A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and the root directive or access log format 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.
When NGINX Plus or NGINX Open Source is configured with sslsessioncache shared:<name>:<size> without an explicit sslsessionticketkey file directive to automatically rotate SSL session ticket keys, a remote unauthenticated attacker is able to forge client SSL sessions in a non-deterministic manner that is beyond the attacker's control. An attacker could leverage this vulnerability to bypass verification of client certificates.
NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpcoremodule 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 cause a worker process to terminate unexpectedly. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.
NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpv3module module. When using HTTP/3 with proxyrequestbuffering on directive, an unauthenticated attacker may be able to inject data in the proxied request.
NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpproxyv2module and ngxhttpgrpcmodule modules. This vulnerability exists when the proxyhttpversion to 2 or grpcpass directives are used to proxy HTTP/2 traffic, the ignoreinvalidheaders directive is set to off, and the largeclientheaderbuffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based 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 6 June 2026
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.
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.
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.
Last updated 2 June 2026
Last updated 6 June 2026
A vulnerability exists in the ngxhttpscgimodule and ngxhttpuwsgimodule modules that may result in excessive memory allocation or an over-read of data. When scgipass or uwsgipass is configured, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to read the memory of the NGINX worker process or restart it. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Last updated 6 June 2026
When NGINX Open Source is configured to proxy HTTP/2 traffic by setting proxyhttpversion to 2, and also uses proxysetbody, an attacker may be able to inject frame headers and payload bytes to the upstream peer. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.