Ingress-nginx Auth-URL Bypass via Misconfigured Custom-Errors
CVE-2026-24513 Published on February 3, 2026

ingress-nginx auth-url protection bypass
A security issue was discovered in ingress-nginx where the protection afforded by the `auth-url` Ingress annotation may not be effective in the presence of a specific misconfiguration. If the ingress-nginx controller is configured with a default custom-errors configuration that includes HTTP errors 401 or 403, and if the configured default custom-errors backend is defective and fails to respect the X-Code HTTP header, then an Ingress with the `auth-url` annotation may be accessed even when authentication fails. Note that the built-in custom-errors backend works correctly. To trigger this issue requires an administrator to specifically configure ingress-nginx with a broken external component.

NVD

Vulnerability Analysis

CVE-2026-24513 can be exploited with network access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
LOW
Integrity Impact:
NONE
Availability Impact:
NONE

Weakness Type

Improper Check for Unusual or Exceptional Conditions

The software does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the software.


Products Associated with CVE-2026-24513

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Affected Versions

Kubernetes ingress-nginx:

Exploit Probability

EPSS
0.01%
Percentile
1.94%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.