Cyber Resilience

CVE-2026-3288

Kubernetes Ingress-Nginx ≤ 1.13.8

Published
09 March 2026
Modified
06 May 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.063 93th percentile
Risk Priority 71 floored blend · peak EPSS

Summary

CVE-2026-3288 is a high-severity Improper Input Validation (CWE-20) vulnerability in Kubernetes Ingress-Nginx. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-3288, published on 2026-03-09, is a vulnerability in the ingress-nginx controller for Kubernetes. It stems from improper handling of the `nginx.ingress.kubernetes.io/rewrite-target` Ingress annotation, which allows attackers to inject arbitrary configuration into the underlying nginx process. This can result in arbitrary code execution within the context of the ingress-nginx controller pod, as well as disclosure of Kubernetes Secrets accessible to the controller. In default installations, the controller has cluster-wide read access to all Secrets. The issue is rated at CVSS v3.1 score 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-20: Improper Input Validation.

Exploitation requires low privileges, specifically the ability to create or modify Ingress resources in a targeted namespace, and can be performed remotely over the network with low complexity and no user interaction. A successful attack grants arbitrary code execution as the ingress-nginx controller, enabling high confidentiality, integrity, and availability impacts. Attackers can also exfiltrate sensitive Secrets, potentially exposing cluster-wide credentials in default configurations.

Advisories and related resources, including the Kubernetes issue tracker (https://github.com/kubernetes/kubernetes/issues/137560), OSS-Security mailing list (http://www.openwall.com/lists/oss-security/2026/03/09/8), and a proof-of-concept lab (https://github.com/bvabhishek/CVE-2026-3288-lab), provide further details on the issue and potential mitigations.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A security issue was discovered in ingress-nginx where the `nginx.ingress.kubernetes.io/rewrite-target` Ingress annotation can be used to inject configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to…

more

the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-5043Same product: Kubernetes Ingress-Nginx
CVE-2023-5044Same product: Kubernetes Ingress-Nginx
CVE-2023-3893Same vendor: Kubernetes
CVE-2026-4342Same vendor: Kubernetes
CVE-2023-2727Same vendor: Kubernetes
CVE-2023-2728Same vendor: Kubernetes
CVE-2023-3676Same vendor: Kubernetes
CVE-2023-3955Same vendor: Kubernetes
CVE-2023-5528Same vendor: Kubernetes
CVE-2024-21549Shared CWE-20

Affected Assets

kubernetes
ingress-nginx
≤ 1.13.8 · 1.14.0 — 1.14.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing input validation through analysis or test cases.

SI-10 directly requires validity checks on information inputs, structurally preventing improper or missing validation.

Requiring documented development standards and tools can embed input-validation practices into the engineering process.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require and enforce input validation during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

prevents

Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.

prevents

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

prevents

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

none

Regular automated validation of system software and data content, combined with scanning of all inbound files, enforces input validation at the boundary before untrusted content is processed.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (1 rule)
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-20

References