Описание
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers 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.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
A flaw was found in NGINX. When NGINX is configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module with specific settings, a remote, unauthenticated attacker can send specially crafted large headers. This can trigger a heap-based buffer overflow, leading to a restart of the NGINX worker process and a Denial of Service (DoS). Under certain conditions, such as when Address Space Layout Randomization (ASLR) is disabled or bypassed, this vulnerability could also allow for arbitrary code execution.
Отчет
This issue is classified as Important severity primarily because: Conditions for Exploitation: A remote, unauthenticated attacker can only exploit this if NGINX is explicitly configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module. Impact Limitations: While the flaw reliably causes a Denial of Service (worker restart), achieving arbitrary code execution is highly complex in modern environments as it requires the attacker to bypass or disable Address Space Layout Randomization (ASLR)
Меры по смягчению последствий
To mitigate this vulnerability, ensure that the ignore_invalid_headers directive is set to on in your NGINX configuration, or reduce the size specified by the large_client_header_buffers directive to 2 megabytes or less. These changes require an NGINX service reload or restart to take effect. Reloading the NGINX service is generally safe, but a restart will briefly interrupt service.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | nginx | Affected | ||
| Red Hat Enterprise Linux 8 | nginx | Affected | ||
| Red Hat Enterprise Linux 9 | nginx | Affected | ||
| Red Hat Enterprise Linux 9 | nginx:1.24/nginx | Affected | ||
| Red Hat Enterprise Linux 9 | nginx:1.26/nginx | Affected | ||
| Red Hat Hardened Images | nginx-main-1.30.3-2.hum1 | Fixed | RHSA-2026:27197 | 19.06.2026 |
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Дополнительная информация
Статус:
8.1 High
CVSS3
Связанные уязвимости
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers 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. 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 ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers 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. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ ...
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers 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. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
8.1 High
CVSS3