CVE-2026-29954

HighPublic PoC

Published: 30 March 2026

Published

30 March 2026

Modified

06 April 2026

KEV Added

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Patch

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CVSS Score 7.6 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:N

EPSS Score 0.0004 13.0th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-29954 is a high-severity Argument Injection (CWE-88) vulnerability in Cloudark Kubeplus. Its CVSS base score is 7.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

SI-10 requires validation of the chartURL input beyond mere URL-encoding to block SSRF by restricting target addresses and neutralize command injection payloads in wget concatenation.

SI-2 Flaw Remediation good match

prevent

SI-2 ensures timely remediation of the SSRF and command injection flaws in KubePlus mutating webhook and kubeconfiggenerator components via patching.

SI-9 Information Input Restrictions partial match

prevent

SI-9 restricts chartURL inputs to approved hosts and formats, mitigating SSRF by preventing access to unauthorized internal or external targets.

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

T1212 Exploitation for Credential Access Credential Access

Adversaries may exploit software vulnerabilities in an attempt to collect credentials.

attack.mitre.org →

Why these techniques?

SSRF + wget argument injection (CWE-88/918) in ResourceComposition processing enables scope-changing privilege escalation (S:C) and high-impact credential/sensitive data access from an already-privileged position.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

In KubePlus 4.1.4, the mutating webhook and kubeconfiggenerator components have an SSRF vulnerability when processing the chartURL field of ResourceComposition resources. The field is only URL-encoded without validating the target address. More critically, when kubeconfiggenerator uses wget to download charts,…

the chartURL is directly concatenated into the command, allowing attackers to inject wget's `--header` option to achieve arbitrary HTTP header injection.

Deeper analysisAI

CVE-2026-29954 is a vulnerability in KubePlus 4.1.4 affecting the mutating webhook and kubeconfiggenerator components. It manifests as a Server-Side Request Forgery (SSRF) when processing the chartURL field of ResourceComposition resources, where the input is only URL-encoded without validation of the target address. More severely, the kubeconfiggenerator directly concatenates the chartURL into a wget command for downloading charts, enabling attackers to inject the wget --header option and achieve arbitrary HTTP header injection. The issue maps to CWE-88 (improper neutralization of argument delimiters) and CWE-918 (SSRF).

Attackers with high privileges (PR:H), such as those with access to create or modify ResourceComposition resources, can exploit this over the network (AV:N) with low complexity (AC:L) and no user interaction (UI:N). Successful exploitation has a high scope (S:C), granting high confidentiality impact (C:H) through SSRF and header injection, low integrity impact (I:L), and no availability impact (A:N), for an overall CVSS v3.1 score of 7.6.

Mitigation details are available in advisories at https://gist.github.com/b0b0haha/33baea60fd2a847f11f1fb02e43c64c0 and https://github.com/b0b0haha/CVE-2026-29954/blob/main/README.md.