CVE-2026-40460
Description
A flaw was found in NGINX Plus and NGINX Open Source when configured to use the HTTP/3 QUIC module. A remote attacker could exploit this by spoofing their source IP address. This vulnerability allows for the bypass of authorization controls or rate limiting mechanisms, potentially leading to unauthorized access or resource abuse.
Mitigation
To mitigate this issue, if the HTTP/3 QUIC module is not required, disable it in your NGINX configuration. This typically involves removing or commenting out the `quic` parameter from `listen` directives in your `nginx.conf` file. After modifying the configuration, a graceful reload or restart of the NGINX service is required for the changes to take effect. For example, use `sudo systemctl reload nginx` or `sudo systemctl restart nginx`.
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 | 6.5 | N/A | 6.5 |
| 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 | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
This weakness can allow an attacker to access resources which are not otherwise accessible without proper authentication.
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