Answer in brief
CVE-2026-42055 records a High severity (CVSS 8.1) vulnerability in NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability. The current sources do not mark it as known exploited. The current feed maps F5/NGINX Open Source (generic), F5/NGINX Plus (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-42055 records a High severity (CVSS 8.1) vulnerability in NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability. The current sources do not mark it as known exploited. The current feed maps F5/NGINX Open Source (generic), F5/NGINX Plus (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps F5/NGINX Open Source (generic), F5/NGINX Plus (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| F5/NGINX Open Sourcegeneric | >=1.13.10 <1.31.2 || >=1.30.2 <1.30.3 | 1.31.2, 1.30.3 |
| F5/NGINX Plusgeneric | >=37.0 <37.0.2.1 || >=R36 <R36 P6 | 37.0.2.1, R36 P6 |
Published upstream
Jun 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 2, 2026
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.
Quoted source text, attributed separately from HOL analysis.
CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps F5/NGINX Open Source (generic), F5/NGINX Plus (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| F5/NGINX Open Sourcegeneric | >=1.13.10 <1.31.2 || >=1.30.2 <1.30.3 | 1.31.2, 1.30.3 |
| F5/NGINX Plusgeneric | >=37.0 <37.0.2.1 || >=R36 <R36 P6 | 37.0.2.1, R36 P6 |
Published upstream
Jun 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 2, 2026
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.
Quoted source text, attributed separately from HOL analysis.