SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-104939

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

HIGH 8.7EPSS 0.38%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.38% probability · 31th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-303
Source
f5sirt@f5.com
EPSS trend
0%3%5%15 October 2026: 0.36%26 October 2026: 0.38%15 October 202626 October 2026

EPSS moved from 0.4% on 15 October 2026 to 0.4% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.