PT-2026-50438 · F5 · Nginx Open Source+1
Published
2026-06-17
·
Updated
2026-06-17
·
CVE-2026-42055
CVSS v3.1
8.1
High
| Vector | AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
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
Heap Based Buffer Overflow
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Weakness Enumeration
Related Identifiers
Affected Products
Nginx Open Source
Nginx Plus