Summary
Kargo has Missing Authorization Vulnerabilities in Approval & Promotion REST API Endpoints
Kargo's authorization model includes a promote verb -- a non-standard Kubernetes "dolphin verb" -- that gates the ability to advance Freight through a promotion pipeline. This verb exists to separate the ability to manage promotion-related resources from the ability to trigger promotions, enabling fine-grained access control over what is often a sensitive operation.
The promote verb is correctly enforced in Kargo's legacy gRPC API. However, three endpoints in the newer REST API omit this check, relying only on standard Kubernetes RBAC for the underlying resource operations (patch on freights/status or create on promotions). This permits users who hold those standard permissions -- but who were deliberately not granted promote -- to bypass the intended authorization boundary.
The affected endpoints are:
POST /v1beta1/projects/{project}/freight/{freight}/approveApproves
Freightfor promotion to a specificStage.The endpoint is intended to require both
patchpermission onFreightstatus andpromotepermission on the targetStage, but asserts only the former.POST /v1beta1/projects/{project}/stages/{stage}/promotionsPromotes
Freightto a specificStage.The endpoint is intended to require both
createpermission onPromotionresources andpromotepermission on the targetStage, but asserts only the former.POST /v1beta1/projects/{project}/stages/{stage}/promotions/downstreamPromotes
Freightto allStages immediately downstream of a givenStage.The endpoint is intended to require both
createpermission onPromotionresources andpromotepermission on each downstreamStage, but asserts only the former.
Base Metrics
The following sections provide the rationale for the values selected for each of CVSS v4's base metrics.
Attack Vector (AV): Network
The affected endpoints are part of Kargo's newer REST API, which is served over HTTP/HTTPS. (The analogous endpoints of the legacy gRPC API correctly check promote permission and are not affected.) No local or physical access is required.
Attack Complexity (AC): Low
The attack requires only well-formed API requests to the affected endpoints.
Attack Requirements (AT): None
No specific environmental conditions are required beyond those that are typical for any Kargo instance.
Privileges Required (PR): Low
The attacker must hold permissions to patch Freight status and/or create Promotion resources. These are standard operational permissions commonly granted to some Kargo users and do not represent what CVSS formally considers administrative or elevated access.
User Interaction (UI): None
The attack is fully automated via API calls. No other user needs to take any action.
Confidentiality Impact to Vulnerable System (VC): None
The vulnerability does not expose any data from the Kargo control plane.
Integrity Impact to Vulnerable System (VI): Low
The attacker can coerce a Stage into a state it might not otherwise transition to. This constitutes bounded state corruption within a single Project. Kargo itself continues to function correctly.
Availability Impact to Vulnerable System (VA): None
Promotion resources created by exploitation of this vulnerability consume the same controller resources as a legitimate Promotion would. A user with proper promote permissions could generate identical load. The vulnerability does not introduce any new avenue for resource exhaustion.
Confidentiality Impact to Subsequent Systems (SC): None
The vulnerability does not provide any mechanism for the attacker to read data from downstream systems.
Integrity Impact to Subsequent Systems (SI): Low
Critically, the attacker does not control the content of Freight resources without artifact repositories also having been compromised. In isolation, which is how vulnerabilities are scored, the worst consequence of a successful attack is downstream systems (e.g. Argo CD) deploying incorrect revisions of artifacts, which in some cases should have been rejected by bypassed segments of the promotion pipeline. Though the operational consequences land on subsequent systems, they are bounded by the attacker's inability to inject arbitrary content.
Availability Impact to Subsequent Systems (SA): None
The attack does not provide any mechanism to degrade the availability of downstream systems beyond what could be achieved with legitimately promoted Freight.
Mitigating Factors
Only the REST API endpoints introduced in v1.9.0 are affected. The legacy gRPC API and the Kargo UI (which uses the gRPC API) correctly enforce the
promotepermission check and are not vulnerable.The window of affected versions is narrow: v1.9.0 through v1.9.2.
Exploitation requires authentication to the Kargo API server and specific operational permissions (
patchonfreights/statusorcreateonpromotions). Anonymous or minimally privileged users cannot exploit this vulnerability.Impact is bounded to a single Project. The
promotebypass does not enable cross-Project access or escalation beyond the namespace in which the attacker already holds the prerequisite permissions.There is no evidence of exploitation in the wild.
Impact
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-27111? CVE-2026-27111 is a medium-severity missing authorization vulnerability in github.com/akuity/kargo (go), affecting versions >= 1.9.0, < 1.9.3. It is fixed in 1.9.3. The application does not perform an authorization check before performing a sensitive operation.
- Which versions of github.com/akuity/kargo are affected by CVE-2026-27111? github.com/akuity/kargo (go) versions >= 1.9.0, < 1.9.3 is affected.
- Is there a fix for CVE-2026-27111? Yes. CVE-2026-27111 is fixed in 1.9.3. Upgrade to this version or later.
- Is CVE-2026-27111 exploitable, and should I be worried? Whether CVE-2026-27111 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-27111 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-27111? Upgrade
github.com/akuity/kargoto 1.9.3 or later.