High severity · published Oct 14, 2026
CVE-2026-104939
NGINX Ingress Controller vulnerability
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NI
NGINX Ingress Controller · F5
5.6.0 before 5.7.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-104939
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-104939
vendor-advisory
https://my.f5.com/manage/s/article/K000162617
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