SB2026070801 - Red Hat Enterprise Linux 10 update for nginx



SB2026070801 - Red Hat Enterprise Linux 10 update for nginx

Published: July 8, 2026

Security Bulletin ID SB2026070801
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Heap-based buffer overflow (CVE-ID: CVE-2026-42055)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code or cause a denial of service.

The vulnerability exists due to heap-based buffer overflow in ngx_http_proxy_v2_module and ngx_http_grpc_module when proxying HTTP/2 traffic with large headers while creating an upstream request. A remote attacker can send large headers to execute arbitrary code or cause a denial of service.

Exploitation requires a non-default configuration in which proxy_http_version is set to 2 or grpc_pass is used, ignore_invalid_headers is set to off, and the large_client_header_buffers per-buffer size is larger than 2 megabytes. This is a data plane issue only.


Remediation

Install update from vendor's website.