F5 Nginx Open Source vulnerabilities

35 vulnerabilities

Known vulnerabilities in F5 Nginx Open Source, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.

8.3CVE-2026-97629debiannginx+3
EPSS score
0.18%
Description When NGINX Plus or NGINX Open Source is configured with ssl_session_cache shared:name:size without an explicit ssl_session_ticket_key file directives 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. Impact This vulnerability can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with access to sensitive information. 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.
9.2CVE-2026-97205debiannginx+3
EPSS score
0.44%
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_core_module 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 a worker process crash. 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, corrupt its memory, or possibly trigger 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.
6.9CVE-2026-95101debiannginx+3
EPSS score
0.25%
Description NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_v3_module module. When using HTTP/3 with proxy_request_buffering 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.
9.2CVE-2026-93479debiannginx+3
EPSS score
0.55%
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.
9.2CVE-2026-15176debiannginx+15
EPSS score
0.52%
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 $request_filename variable. Alternatively, the same result could be achieved when the $request_filename 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.
6.3CVE-2025-53859alpinenginx+40
EPSS score
0.41%
NGINX Open Source and NGINX Plus have a vulnerability in the ngx_mail_smtp_module that might allow an unauthenticated attacker to over-read NGINX SMTP authentication process memory; as a result, the server side may leak arbitrary bytes sent in a request to the authentication server. This issue happens during the NGINX SMTP authentication process and requires the attacker to make preparations against the target system to extract the leaked data. The issue affects NGINX only if (1) it is built with the ngx_mail_smtp_module, (2) the smtp_auth directive is configured with method "none," and (3) the authentication server returns the "Auth-Wait" response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
5.3CVE-2025-23419alpinenginx+34
EPSS score
2.79%
When multiple server blocks are configured to share the same IP address and port, an attacker can use session resumption to bypass client certificate authentication requirements on these servers. This vulnerability arises when TLS Session Tickets https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key are used and/or the SSL session cache https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache are used in the default server and the default server is performing client certificate authentication.   Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
4.8CVE-2024-31079alpinenginx+34
EPSS score
0.89%
When NGINX Plus or NGINX OSS are configured to use the HTTP/3 QUIC module, undisclosed HTTP/3 requests can cause NGINX worker processes to terminate or cause other potential impact. This attack requires that a request be specifically timed during the connection draining process, which the attacker has no visibility and limited influence over.
5.7CVE-2024-7347alpinenginx+24
EPSS score
0.32%
NGINX Open Source and NGINX Plus have a vulnerability in the ngx_http_mp4_module, which might allow an attacker to over-read NGINX worker memory resulting in its termination, using a specially crafted mp4 file. The issue only affects NGINX if it is built with the ngx_http_mp4_module and the mp4 directive is used in the configuration file. Additionally, the attack is possible only if an attacker can trigger the processing of a specially crafted mp4 file with the ngx_http_mp4_module.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
7.5CVE-2024-24990chainguardnginx-mainline+4
EPSS score
0.91%
When NGINX Plus or NGINX OSS are configured to use the HTTP/3 QUIC module, undisclosed requests can cause NGINX worker processes to terminate. Note: The HTTP/3 QUIC module is not enabled by default and is considered experimental. For more information, refer to Support for QUIC and HTTP/3 https://nginx.org/en/docs/quic.html . Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
7.5CVE-2024-24989chainguardnginx-mainline+5
EPSS score
1.06%
When NGINX Plus or NGINX OSS are configured to use the HTTP/3 QUIC module, undisclosed requests can cause NGINX worker processes to terminate. Note: The HTTP/3 QUIC module is not enabled by default and is considered experimental. For more information, refer to Support for QUIC and HTTP/3 https://nginx.org/en/docs/quic.html . NOTE: Software versions which have reached End of Technical Support (EoTS) are not evaluated
6.5CVE-2024-32760alpinenginx+34
EPSS score
0.86%
When NGINX Plus or NGINX OSS are configured to use the HTTP/3 QUIC module, undisclosed HTTP/3 encoder instructions can cause NGINX worker processes to terminate or cause or other potential impact.
5.3CVE-2024-34161alpinenginx+34
EPSS score
0.87%
When NGINX Plus or NGINX OSS are configured to use the HTTP/3 QUIC module and the network infrastructure supports a Maximum Transmission Unit (MTU) of 4096 or greater without fragmentation, undisclosed QUIC packets can cause NGINX worker processes to leak previously freed memory.
5.3CVE-2024-35200alpinenginx+34
EPSS score
0.93%
When NGINX Plus or NGINX OSS are configured to use the HTTP/3 QUIC module, undisclosed HTTP/3 requests can cause NGINX worker processes to terminate.
6.3CVE-2026-40701alpinenginx+13
EPSS score
0.69%
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_module module when the ssl_verify_client directive is set to "on" or "optional," and the ssl_ocsp directive is set to "on" or the leaf parameters are configured with a resolver. With this configuration, an unauthenticated attacker can send requests along with conditions beyond its control that may cause a heap-use-after-free error in the NGINX worker process. This vulnerability may result in limited modification of data or the NGINX worker process restarting.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
6.9CVE-2026-40460alpinenginx+13
EPSS score
0.38%
When NGINX Plus or NGINX Open Source are configured to use the HTTP/3 QUIC module, an attacker may be able to spoof their source IP address allowing for bypass of authorization or bypass of rate limiting.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
8.2CVE-2026-1642alpinenginx+63
EPSS score
0.39%
A vulnerability exists in NGINX OSS and NGINX Plus when configured to proxy to upstream Transport Layer Security (TLS) servers. An attacker with a man-in-the-middle (MITM) position on the upstream server side—along with conditions beyond the attacker's control—may be able to inject plain text data into the response from an upstream proxied server.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
6.3CVE-2026-42926alpinenginx+10
EPSS score
0.34%
When NGINX Open Source is configured to proxy HTTP/2 traffic by setting proxy_http_version to 2, and also uses proxy_set_body, 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.
9.2CVE-2026-42945alpinenginx+88
EPSS score
3.40%
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its 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.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
9.2CVE-2026-42533alpinenginx+41
EPSS score
0.89%
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. 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.