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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
F5 NGINX Open Source unknown
Version Status Constraints
1.3.0 affected < 1.29.5
F5 NGINX Plus unknown
Version Status Constraints
R36 affected < R36 P2
R35 affected < R35 P1
R34 affected < *
R33 affected < *
R32 affected < R32 P4

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://my.f5.com/manage/s/article/K000159824 cve-icon cve-icon
History

Wed, 04 Feb 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 04 Feb 2026 15:15:00 +0000

Type Values Removed Values Added
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.
Title NGINX vulnerability
Weaknesses CWE-349
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: f5

Published:

Updated: 2026-02-04T16:02:24.781Z

Reserved: 2026-01-29T18:26:26.996Z

Link: CVE-2026-1642

cve-icon Vulnrichment

Updated: 2026-02-04T16:02:17.994Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-04T15:16:14.190

Modified: 2026-02-04T16:33:44.537

Link: CVE-2026-1642

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses