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.
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-24513",
"assignerOrgId": "a6081bf6-c852-4425-ad4f-a67919267565",
"assignerShortName": "kubernetes",
"dateUpdated": "2026-02-03T22:17:17.315Z",
"dateReserved": "2026-01-23T06:54:35.913Z",
"datePublished": "2026-02-03T22:17:17.315Z",
"state": "PUBLISHED"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "a6081bf6-c852-4425-ad4f-a67919267565",
"shortName": "kubernetes",
"dateUpdated": "2026-02-03T22:17:17.315Z"
},
"datePublic": "2026-02-02T14:00:00.000Z",
"title": "ingress-nginx auth-url protection bypass",
"descriptions": [
{
"lang": "en",
"value": "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.\n\nIf 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.\n\nNote 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.",
"supportingMedia": [
{
"type": "text/html",
"base64": false,
"value": "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.<br>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.<br>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."
}
]
}
],
"affected": [
{
"vendor": "Kubernetes",
"product": "ingress-nginx",
"repo": "https://github.com/kubernetes/ingress-nginx",
"defaultStatus": "affected",
"versions": [
{
"version": "0",
"status": "affected",
"versionType": "semver",
"lessThan": "1.13.7"
},
{
"version": "0",
"status": "affected",
"versionType": "semver",
"lessThan": "1.14.2"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "CWE-754 Improper Check for Unusual or Exceptional Conditions",
"cweId": "CWE-754",
"type": "CWE"
}
]
}
],
"references": [
{
"url": "https://github.com/kubernetes/kubernetes/issues/136679"
}
],
"impacts": [
{
"capecId": "CAPEC-115",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-115 Authentication Bypass"
}
]
}
],
"metrics": [
{
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
],
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"availabilityImpact": "NONE",
"baseScore": 3.1,
"baseSeverity": "LOW"
}
}
]
}
}
}