SB2026070801 - Red Hat Enterprise Linux 10 update for nginx
Published: July 8, 2026
Breakdown by Severity
- 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.