CVE-2026-42055

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 is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server.

Security Fix(es):

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.(CVE-2026-42055)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset 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.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.(CVE-2026-48142)

NGINX is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server.

Security Fix(es):

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.(CVE-2026-42055)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset 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.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.(CVE-2026-48142)

NGINX is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server.

Security Fix(es):

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.(CVE-2026-42055)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset 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.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.(CVE-2026-48142)

NGINX is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server.

Security Fix(es):

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.(CVE-2026-42055)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset 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.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.(CVE-2026-48142)

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• nginx: "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [rhel-9.8.z] (JIRA:Rocky Linux-190800)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [rhel-10.2.z] (JIRA:Rocky Linux-191778)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• nginx:1.24/nginx: "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [rhel-9.8.z] (JIRA:Rocky Linux-191773)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• nginx:1.26/nginx: "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [rhel-9.8.z] (JIRA:Rocky Linux-191774)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [rhel-8.10.z] (JIRA:Rocky Linux-191779)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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 is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• nginx: "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [almalinux-9.8.z] (JIRA:AlmaLinux-190800)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [almalinux-10.2.z] (JIRA:AlmaLinux-191778)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• nginx:1.24/nginx: "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [almalinux-9.8.z] (JIRA:AlmaLinux-191773)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• nginx:1.26/nginx: "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [almalinux-9.8.z] (JIRA:AlmaLinux-191774)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

nginx is a web and proxy server supporting HTTP and other protocols, with a focus on high concurrency, performance, and low memory usage.

Security Fix(es):

• nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers (CVE-2026-42055)

Bug Fix(es) and Enhancement(s):

• "HTTP/2 bomb" nginx fix breaks module ABI causing crashes [almalinux-8.10.z] (JIRA:AlmaLinux-191779)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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 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.

• fix CVE-2026-42055: HPACK field-length validation in HTTP/2 gRPC request builder and HTTP/2 response header filter; fields exceeding NGX_HTTP_V2_MAX_FIELD now return NGX_ERROR instead of overflowing the 4-byte HPACK length prefix

• CVE-2026-42055: fix heap buffer overflow when proxying HTTP/2/gRPC upstream with oversized (>2M) request header fields

• CVE-2026-42055: fix heap buffer overflow when proxying HTTP/2/gRPC upstream with oversized (>2M) request header fields

• CVE-2026-42055: fix heap buffer overflow when proxying HTTP/2/gRPC upstream with oversized (>2M) request header fields

• CVE-2026-42055: limit HTTP/2 header field length in ngx_http_grpc_module to avoid heap buffer overflow when proxying to a gRPC upstream

• SECURITY UPDATE: Heap buffer overflow in ngx_http_grpc_module when proxying oversized headers to a gRPC/HTTP/2 upstream
  • debian/patches/CVE-2026-42055.patch: reject request line and header fields longer than NGX_HTTP_V2_MAX_FIELD in ngx_http_grpc_create_request to prevent buffer overrun when large_client_header_buffers exceeds 2 megabytes and ignore_invalid_headers is off
  • CVE-2026-42055

• SECURITY UPDATE: heap buffer overflow via oversized HTTP/2 and gRPC upstream request headers
  • debian/patches/CVE-2026-42055.patch: reject header fields longer than NGX_HTTP_V2_MAX_FIELD in ngx_http_grpc_create_request() before the upstream request buffer length is computed, and in ngx_http_v2_header_filter() for the Content-Type and Location response header values
  • CVE-2026-42055

• SECURITY UPDATE: buffer overflow in the gRPC upstream request builder via overlong HTTP/2 header fields
  • debian/patches/CVE-2026-42055.patch: reject a method name, URI, host, configured header name or value, or forwarded client header name or value longer than NGX_HTTP_V2_MAX_FIELD in ngx_http_grpc_create_request(), so an oversized field can no longer overflow the HPACK integer encoding the request buffer was sized for
  • CVE-2026-42055

ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability. (CVE-2026-42055) ngx_http_charset_module vulnerability. (CVE-2026-48142)

These are all security issues fixed in the nginx-1.31.2-1.1 package on the GA media of openSUSE Tumbleweed.

This update for nginx fixes the following issues

• CVE-2026-40460: bypass of authorization and bypass of rate limiting when NGINX is configured to use the HTTP/3 QUIC module (bsc#1265228).
• CVE-2026-42055: heap-based buffer overflow in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules (bsc#1268492).
• CVE-2026-48142: heap buffer over-read in the ngx_http_charset_module module (bsc#1268495).
• HTTP2-BOMB denial of service (bsc#1267525).

This update for nginx fixes the following issues

• CVE-2026-40460: bypass of authorization and bypass of rate limiting when NGINX is configured to use the HTTP/3 QUIC module (bsc#1265228).
• CVE-2026-42055: heap-based buffer overflow in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules (bsc#1268492).
• CVE-2026-48142: heap buffer over-read in the ngx_http_charset_module module (bsc#1268495).
• HTTP2-BOMB denial of service (bsc#1267525).

This update for nginx fixes the following issues

• CVE-2026-40460: bypass of authorization and bypass of rate limiting when NGINX is configured to use the HTTP/3 QUIC module (bsc#1265228).
• CVE-2026-42055: heap-based buffer overflow in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules (bsc#1268492).
• CVE-2026-48142: heap buffer over-read in the ngx_http_charset_module module (bsc#1268495).
• HTTP2-BOMB denial of service (bsc#1267525).

This update for nginx fixes the following issues

• CVE-2026-42055: heap-based buffer overflow in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules (bsc#1268492).
• CVE-2026-48142: heap buffer over-read in the ngx_http_charset_module module (bsc#1268495).
• Remote denial of service via the HTTP/2 bomb exploit (bsc#1267525).

This update for nginx fixes the following issues:

• CVE-2026-42055: heap buffer overflow in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules (bsc#1268492).
• CVE-2026-42533: heap buffer overflow in the map directive and regex matching (bsc#1271514).
• CVE-2026-48142: heap buffer overread in the ngx_http_charset_module module (bsc#1268495).
• Remote denial of service via the HTTP/2 bomb exploit (bsc#1267525).

It was discovered that nginx incorrectly handled large headers when proxying HTTP/2 traffic. A remote attacker could use this issue to cause nginx to crash, resulting in a denial of service, or possibly execute arbitrary code. The default compiler options for affected releases should reduce the vulnerability to a denial of service. (CVE-2026-42055)

It was discovered that nginx incorrectly handled character set conversion under certain circumstances. A remote attacker could possibly use this issue to obtain sensitive information or cause nginx to crash, resulting in a denial of service. (CVE-2026-48142)