CVE-2021-25748
Ingress-nginx `path` sanitization can be bypassed with newline character
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Ingress-nginx `path` sanitization can be bypassed with newline character
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.
- Record
CVE-2021-25748- CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2023-1500
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.
- Record
EUVD-2023-1500- CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-863x-868h-968x
Ingress-nginx `path` sanitization can be bypassed with newline character
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.
- Record
GHSA-863x-868h-968x- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-25748- CVSS 3.1
- 7.6 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-25748- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-863x-868h-968x
Ingress-nginx `path` sanitization can be bypassed with newline character
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.
- Record
GHSA-863x-868h-968x- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
k8s.io/ingress-nginxGo |
before 1.2.1 | 1.2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-25748 is a high vulnerability (CVSS 7.6) in Kubernetes Ingress-nginx, published May 24, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.69%, the 53rd percentile. Fixed in k8s.io/ingress-nginx 1.2.1.
References
groups.google.com/g/kubernetes-security-announce/c/avaRYa9c7I8
github.com/kubernetes/ingress-nginx/issues/8686
nvd.nist.gov/vuln/detail/CVE-2021-25748