CVE-2026-1642

NGINX vulnerability

MEDIUM

5.9

CVSS Score

Published: February 4, 2026 at 03:02 PM UTC

Updated: June 17, 2026 at 10:16 AM UTC

5 products affected across 1 vendorNGINX PlusNGINX Open SourceNGINX Ingress Controller

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Severity

MEDIUM5.9

Exploit prediction

EPSS 0.4%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

NGINX Gateway Fabric · F5

95%

1.2.0 ≤ v ≤ 1.6.22.0.0 ≤ v < 2.4.1

NGINX Ingress Controller · F5

95%

3.4.0 ≤ v ≤ 3.7.24.0.0 ≤ v ≤ 4.0.15.0.0 ≤ v < 5.3.3

NGINX Instance Manager · F5

95%

2.15.1 ≤ v ≤ 2.21.0

NGINX Open Source · F5

95%

1.29.0 ≤ v < 1.29.51.3.0 ≤ v < 1.28.21.3.0 ≤ v < 1.29.51.3.0

Affected range stops below 1.29.5, so it looks safe — our inference, not a vendor statement

NGINX Plus · F5

95%

v ≥ R33v ≥ R34R32 ≤ v < R32 P4R35 ≤ v < R35 P1R36 ≤ v < R36 P2r33 ≤ v < r35R32 R33 R34 R35 R36 r32 r32 p1 r32 p2 r32 p3 r33 p1 r33 p2 r33 p3 r34 p1 r34 p2r35r36 r36 p1

Affected range stops below R32 P4, so it looks safe — our inference, not a vendor statement

Affected range stops below R35 P1, so it looks safe — our inference, not a vendor statement

Affected range stops below R36 P2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://my.f5.com/manage/s/article/K000159824

References (2)

Vendor Advisory

Source: cverecord

https://my.f5.com/manage/s/article/K000159824

Mailing ListThird Party Advisory

Source: af854a3a-2127-422b-91ae-364da2661108

http://www.openwall.com/lists/oss-security/2026/02/05/1

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMf5

Attack Vector: NETWORK
Complexity: HIGH
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: HIGH
Availability: NONE

Vector?

Quick Info

StatusANALYZED

CWE

CWE-349CWE-345

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