CVE-2026-95101
Description
A flaw was found in NGINX. When HTTP/3 is used with proxy request buffering enabled, an unauthenticated remote attacker can inject arbitrary data into proxied requests. This vulnerability allows an attacker to manipulate traffic forwarded to backend servers, compromising data integrity.
Statement
A flaw was found in NGINX within the HTTP/3 module (ngx_http_v3_module). When HTTP/3 is configured and proxy_request_buffering is active, an unauthenticated remote attacker can inject arbitrary data into proxied client requests. An attacker can exploit this condition to manipulate request payloads forwarded to upstream backend services, compromising data integrity at the proxy layer. Default SELinux confinement (httpd_t) and unprivileged worker execution prevent privilege escalation or container escape, restricting the impact entirely to the proxied HTTP data stream.
Mitigation
Disable HTTP/3 by removing the quic parameter from all listen directives, or configure proxy_request_buffering off; within the relevant http, server, or location blocks.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Understanding the Weakness (CWE)
Integrity,Non-Repudiation,Access Control
Technical Impact: Unexpected State; Hide Activities; Bypass Protection Mechanism
An attacker could create HTTP messages to exploit a number of weaknesses including 1) the message can trick the web server to associate a URL with another URL's webpage and caching the contents of the webpage (web cache poisoning attack), 2) the message can be structured to bypass the firewall protection mechanisms and gain unauthorized access to a web application, and 3) the message can invoke a script or a page that returns client credentials (similar to a Cross Site Scripting attack).
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