CVE-2026-42055

HIGH

NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-42055. PoCs published by HORKimhab.

AI-analyzed exploit summary The repository lacks actual exploit code or technical details about CVE-2026-42055, instead providing generic setup instructions and a vague README with no vulnerability-specific information. It references an external script for cleanup, which is a common red flag for suspicious repositories.

Description

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.

Exploits (1)

github SUSPICIOUS
by HORKimhab · poc
https://github.com/HORKimhab/CVE-2026-42055

The repository lacks actual exploit code or technical details about CVE-2026-42055, instead providing generic setup instructions and a vague README with no vulnerability-specific information. It references an external script for cleanup, which is a common red flag for suspicious repositories.

Classification
Suspicious 90%
Attack Type
Other
Complexity
Theoretical
Reliability
Theoretical
Target: unknown
No auth needed
Prerequisites: none specified
devstral-2 · analyzed Jun 19, 2026 Full analysis →

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory
https://my.f5.com/manage/s/article/K000161584

Scores

CVSS v3 8.1
EPSS 0.0064
EPSS Percentile 45.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-122
Status published
Products (4)
F5/NGINX Open Source 1.13.10 - 1.31.2
F5/NGINX Open Source 1.30.2 - 1.30.3
F5/NGINX Plus 37.0 - 37.0.2.1
F5/NGINX Plus R36 - R36 P6
Published Jun 17, 2026
Tracked Since Jun 17, 2026