A vulnerability exists in NGINX Plus and NGINX Open Source when a location is configured that uses the alias directive together with rewrite and a set or return directive referencing the $requestfilename variable. Alternatively, the same result could be achieved when the $requestfilename variable is used in an access log format directive. 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.

NGINX ngxhttpcoremodule vulnerability

NGINX ngxhttpproxyv2module and ngxhttpgrpcmodule vulnerability

NGINX ngxhttpcharsetmodule vulnerability

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.

Last updated 6 June 2026

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.

A vulnerability exists in NGINX Plus and NGINX Open Source when a location is configured that uses the alias directive together with rewrite and a set or return directive referencing the $requestfilename variable. Alternatively, the same result could be achieved when the $requestfilename variable is used in an access logformat directive. 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 Open Source has a vulnerability in the ngxhttpv3module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free 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.

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

NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpcharsetmodule module. When content is served or proxied through a location block with both sourcecharset utf-8; and a charset directive (for example, charset koi8-r;) configured, remote, unauthenticated attackers can send requests (in conjunction with conditions beyond their control) to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.