CVE-2026-1642 MEDIUM

CVE-2026-1642: NGINX vulnerability

Vendor F5
Product NGINX Open Source
Weakness CWE-349
Published February 4, 2026
Last update February 5, 2026

CVSS base score

5.9/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

What the vulnerability does

Description

A vulnerability exists in NGINX OSS and NGINX Plus when configured to proxy to upstream Transport Layer Security (TLS) servers. An attacker with a man-in-the-middle (MITM) position on the upstream server side—along with conditions beyond the attacker's control—may be able to inject plain text data into the response from an upstream proxied server.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Key dates

Disclosure timeline

February 4, 2026 CVE published
February 5, 2026 Record updated