Ingress-nginx `path` sanitization can be bypassed with newline character
Priority LOW 34CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00694 53rd percentileScored 2026-11-07
Fix Fixed Kubernetes ingress-nginx (Kubernetes): 1.2.1k8s.io/ingress-nginx (Go): 1.2.1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Kubernetes | Kubernetes ingress-nginx | before 1.2.1 | 1.2.1 | Patch available | CNA |
| — | k8s.io/ingress-nginx (Go) | before 1.2.1 | 1.2.1 | Patch available | GHSA-863x-868h-968x |
- Kubernetes ingress-nginx VendorKubernetes Affected before 1.2.1 Fixed in 1.2.1 Patch available CNA
- k8s.io/ingress-nginx (Go) Vendor— Affected before 1.2.1 Fixed in 1.2.1 Patch available GHSA-863x-868h-968x
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:kubernetes:ingress-nginx:*:*:*:*:*:*:*:* | before 1.2.1 | Vulnerable | Kubernetes |
- cpe:2.3:a:kubernetes:ingress-nginx:*:*:*:*:*:*:*:* Versions before 1.2.1 Vulnerable ·Kubernetes
Remediation
- Fix · CNA Kubernetes ingress-nginx (Kubernetes) Fixed in 1.2.1
- Fix · GHSA-863x-868h-968x k8s.io/ingress-nginx (Go) Fixed in 1.2.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2021-25748
- 2026-10-03 Alias added: GHSA-863x-868h-968x
References
Advisory 3
More Kubernetes Ingress-nginx vulnerabilities
- TI-2026-02839 ingress-nginx rewrite-target nginx configuration injection CVSS 3.1HIGH 8.8
- TI-2023-04644 Improper input validation in Kubernetes ingress-nginx CVSS 3.1HIGH 8.8
- TI-2023-04643 Improper input validation in Kubernetes ingress-nginx CVSS 3.1HIGH 8.8
- TI-2022-04479 Improper input validation in Kubernetes ingress-nginx CVSS 3.1HIGH 8.8
- TI-2021-07835 Ingress-nginx path can be pointed to service account token file CVSS 3.1HIGH 8.1
- TI-2021-07833 Ingress-nginx custom snippets allows retrieval of ingress-nginx serviceaccount token and secrets across all namespaces CVSS 3.1HIGH 7.6
Sources
- CVE-2021-25748 · CVE Program
- CVE-2021-25748 · NVD
- FIRST EPSS
- GHSA-863x-868h-968x · GitHub Advisory Database · CC BY 4.0
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