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CVE-2026-104939

7.5, high

Description NGINX Ingress Controller has a vulnerability when implementing an externalAuth policy for ingress

CVSS
7.5, high high CVSS v3.1
EPSS, next 30 days
0.4% higher than 28% of scored CVEs
Exploitation
No public evidence
Published
14 Oct 20263 days ago

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.

Details

Vendor
F5
Product
NGINX Ingress Controller
Weakness
CWE-303 (opens in a new tab)
Status
Awaiting analysis
Updated
14 Oct 2026
Assigner
f5sirt@f5.com

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-94127 F5 BIG-IP APM Heap-based Buffer Overflow Vulnerability KEV EPSS 2% 9.8, critical
  • CVE-2025-53521 F5 BIG-IP Stack-Based Buffer Overflow Vulnerability KEV EPSS 2% 9.8, critical
  • CVE-2023-46747 F5 BIG-IP Configuration Utility Authentication Bypass Vulnerability KEV EPSS 97% 9.8, critical
  • CVE-2023-46748 F5 BIG-IP Configuration Utility SQL Injection Vulnerability KEV EPSS 4% 8.8, high
  • CVE-2022-1388 F5 BIG-IP Missing Authentication Vulnerability KEV EPSS 100% 9.8, critical
  • CVE-2021-22986 F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution Vulnerability KEV EPSS 100% 9.8, critical
  • CVE-2021-22991 F5 BIG-IP Traffic Management Microkernel Buffer Overflow KEV EPSS 61% 9.8, critical
  • CVE-2020-5902 F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution Vulnerability KEV EPSS 100% 9.8, critical

Beyond this page

Is CVE-2026-104939 in your network?

This page tells you how dangerous CVE-2026-104939 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.