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CVE-2026-104939
Published:October 14, 2026
Updated:October 22, 2026
Description NGINX Ingress Controller has a vulnerability when implementing an externalAuth policy for ingress. NGINX Ingress Controller may mishandle the HTTP response from an OAuth IdP and allow an attacker to acquire unauthenticated access to protected paths before the proper external authentication can happen. Impact This vulnerability may allow remote attackers unauthenticated access to protected paths. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Affected Packages
https://github.com/nginx/kubernetes-ingress.git (GITHUB):
Affected version(s) >=v5.6.0 <v5.7.0
Fix Suggestion:
Update to version v5.7.0
github.com/nginx/kubernetes-ingress (GO):
Affected version(s) >=v5.6.0 <v5.7.0
Fix Suggestion:
Update to version v5.7.0
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CVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Incorrect Implementation of Authentication Algorithm
EPSS
Base Score:
0.36