Vulnerability Monitor

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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.


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.1, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 9 products from f5, from f5, from f5 and 6 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2026-06-17T15:16:50.353

Last Modified

2026-07-15T02:21:24.690

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 8.1 (HIGH)

Weaknesses
  • Type: Secondary
    CWE-122
  • Type: Primary
    CWE-787
  • Type: Secondary
    CWE-131

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application f5 dos 4.9.0 Yes
Application f5 nginx_app_protect_dos ≤ 4.7.0 Yes
Application f5 nginx_app_protect_waf ≤ 4.16.0 Yes
Application f5 nginx_app_protect_waf ≤ 5.8.0 Yes
Application f5 nginx_gateway_fabric ≤ 1.6.2 Yes
Application f5 nginx_gateway_fabric < 2.6.4 Yes
Application f5 nginx_ingress_controller ≤ 3.7.2 Yes
Application f5 nginx_ingress_controller < 5.5.1 Yes
Application f5 nginx_ingress_controller 4.0.0 Yes
Application f5 nginx_ingress_controller 4.0.1 Yes
Application f5 nginx_instance_manager ≤ 2.22.0 Yes
Application f5 nginx_open_source < 1.30.3 Yes
Application f5 nginx_open_source 1.31.1 Yes
Application f5 nginx_plus ≤ 37.0.1 Yes
Application f5 nginx_plus r3 Yes
Application f5 nginx_plus r30 Yes
Application f5 nginx_plus r30 Yes
Application f5 nginx_plus r30 Yes
Application f5 nginx_plus r31 Yes
Application f5 nginx_plus r31 Yes
Application f5 nginx_plus r31 Yes
Application f5 nginx_plus r31 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r32 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r33 Yes
Application f5 nginx_plus r34 Yes
Application f5 nginx_plus r34 Yes
Application f5 nginx_plus r34 Yes
Application f5 nginx_plus r35 Yes
Application f5 nginx_plus r35 Yes
Application f5 nginx_plus r36 Yes
Application f5 nginx_plus r36 Yes
Application f5 nginx_plus r36 Yes
Application f5 nginx_plus r36 Yes
Application f5 nginx_plus r36 Yes
Application f5 nginx_plus r36 Yes
Application f5 waf ≤ 5.13.1 Yes
Application f5 waf 4.8.1 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For f5's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.