CVE-2026-1642: NGINX vulnerability

Published Feb 4, 2026
·
Updated

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.

Affected Software

31 affected componentsFixes available
Nginx NGINX OSS
Nginx NGINX Plus
F5 NGINX Gateway Fabric>=1.2.0<=1.6.2
F5 NGINX Gateway Fabric>=2.0.0<2.4.1
F5 NGINX Ingress Controller>=3.4.0<=3.7.2
F5 NGINX Ingress Controller>=4.0.0<=4.0.1
F5 NGINX Ingress Controller>=5.0.0<5.3.3
F5 NGINX Instance Manager>=2.15.1<=2.21.0
F5 NGINX Open Source>=1.3.0<1.28.2
F5 NGINX Open Source>=1.29.0<1.29.5
F5 NGINX Plus>=r33<r35
F5 NGINX Plus=r32
F5 NGINX Plus=r32-p1
F5 NGINX Plus=r32-p2
F5 NGINX Plus=r32-p3
F5 NGINX Plus=r33-p1
F5 NGINX Plus=r33-p2
F5 NGINX Plus=r33-p3
F5 NGINX Plus=r34-p1
F5 NGINX Plus=r34-p2
F5 NGINX Plus=r35
F5 NGINX Plus=r36
F5 NGINX Plus=r36-p1
F5 NGINX Plus=32
36
F5 NGINX Open Source>=1.3.0<=1.29.4
1.29.51.28.2
F5 NGINX Ingress Controller>=5.0.0<=5.3.2
5.3.3
F5 NGINX Ingress Controller>=4.0.0<=4.0.1
F5 NGINX Ingress Controller>=3.4.0<=3.7.2
F5 NGINX Gateway Fabric>=2.0.0<=2.4.0
2.4.1
F5 NGINX Gateway Fabric>=1.2.0<=1.6.2
F5 NGINX Instance Manager>=2.15.1<=2.21.0
2.21.1

Event History

Feb 4, 2026
Advisory Published
via F5·01:40 PM
Data Sourced
via F5·01:40 PM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·03:02 PM
Data Sourced
via MITRE·03:02 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:16 PM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·04:01 PM
DescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-1642?

CVE-2026-1642 has a moderate severity rating due to potential man-in-the-middle vulnerabilities in NGINX OSS and NGINX Plus.

2

How do I fix CVE-2026-1642?

To remediate CVE-2026-1642, upgrade to the latest patched versions of NGINX OSS or NGINX Plus as specified by F5.

3

Which versions of NGINX are affected by CVE-2026-1642?

CVE-2026-1642 affects various versions of NGINX OSS and NGINX Plus, particularly those configured to proxy upstream TLS servers.

4

Can a man-in-the-middle attack exploit CVE-2026-1642?

Yes, an attacker positioned for a man-in-the-middle attack can exploit CVE-2026-1642 under specific circumstances.

5

Is NGINX Ingress Controller impacted by CVE-2026-1642?

Yes, specific versions of NGINX Ingress Controller are also impacted by CVE-2026-1642.

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