Vulnerability record · CVE-2021-25748 · published 24 May 2023

CVE-2021-25748: Kubernetes ingress-nginx improper input validation vulnerability

Kubernetes · Ingress Nginx

A security issue was discovered in ingress-nginx where a user that can create or update ingress objects can use a newline character to bypass the sanitization of the `spec.rules[].http.paths[].path` field of an Ingress object (in the `networking.k8s.io` or `extensions` API group) to obtain the credentials of the ingress-nginx controller. In the default configuration, that credential has access to all secrets in the cluster.

6.5 CVSS 3.1 Medium EPSS 0.69% · top 49.0% CWE-20 · Improper input validation

6.5CVSS 3.1 base score

0.69%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

4References

17 Jun 2026Last modified by NVD

Description

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Ingress Nginx Kubernetes

References

Link	Tags
https://github.com/kubernetes/ingress-nginx/issues/8686	Issue TrackingMitigationVendor Advisory
https://groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8	Mailing ListMitigationVendor Advisory
https://github.com/kubernetes/ingress-nginx/issues/8686	Issue TrackingMitigationVendor Advisory
https://groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8	Mailing ListMitigationVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-25748), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.