nginx 1.13.10 < 1.30.3 / 1.31.x < 1.31.2 Buffer Overflow

high Nessus Plugin ID 321534

Synopsis

The remote web server is affected by a buffer overflow vulnerability.

Description

The installed version of nginx is 1.13.10 prior to 1.30.3, or 1.31.x prior to 1.31.2. It is, therefore, affected by the following issue :

- 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. (CVE-2026-42055)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to nginx 1.30.3 / 1.31.2 or later.

Plugin Details

Severity: High

ID: 321534

File Name: nginx_CVE-2026-42055.nasl

Version: 1.1

Type: Combined

Agent: unix

Family: Web Servers

Published: 6/19/2026

Updated: 6/19/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-42055

CVSS v3

Risk Factor: High

Base Score: 8.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/a:nginx:nginx

Required KB Items: Settings/ParanoidReport, installed_sw/nginx

Patch Publication Date: 6/17/2026

Vulnerability Publication Date: 6/17/2026

Reference Information

CVE: CVE-2026-42055

IAVA: 2026-A-0601

Detections

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