Skip to content

Kargo Vulnerable to SSRF in Promotion http/http-download Steps Enables Internal Network Access and Data Exfiltration

Moderate severity GitHub Reviewed Published Mar 14, 2026 in akuity/kargo • Updated Mar 16, 2026

Package

gomod github.com/akuity/kargo (Go)

Affected versions

>= 1.4.0, < 1.6.4
>= 1.7.0-rc.1, < 1.7.9
>= 1.8.0-rc.1, < 1.8.12
>= 1.9.0-rc.1, < 1.9.5

Patched versions

1.6.4
1.7.9
1.8.12
1.9.5

Description

Summary

Kargo's built-in http and http-download promotion steps execute outbound HTTP requests from the Kargo controller. By design, these steps do not restrict destination addresses, as there are legitimate use cases for requests to internal and private endpoints. However, this also permits requests to link-local addresses, for which there are no known, legitimate use cases. Of particular concern is the cloud instance metadata endpoint (often 169.254.169.254), which is unauthenticated and can expose sensitive configuration data including IAM credentials. While cloud providers typically implement header-based SSRF mitigations for these endpoints, the http step provides full control over request method and headers, rendering these protections ineffective. The http-download step provides control over headers only (not method), but this is still sufficient for exfiltrating data from metadata endpoints.

There are two vectors for exploitation. A user with permission to create or update a Stage can configure its promotion template to include malicious http or http-download steps. Alternatively, a user with promote permission on any Stage can craft a Promotion resource directly. In either case, the controller executes the steps in-cluster, and response data can be inserted into Promotion status fields, written to a Git repository, or sent to a remote location using a second instance of the http step.

The remediation for this issue is the introduction of a safe HTTP transport that refuses to dial link-local addresses. Requests to private and internal addresses will continue to be permitted, as this is by design. It is the responsibility of services at such addresses to implement proper authentication and authorization, and/or the responsibility of platform teams to define and enforce network policies that restrict traffic appropriately.

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 Kargo API server is accessible over HTTP/HTTPS. No local, adjacent network, or physical access is required.

Attack Complexity (AC): Low

Exploitation requires only a crafted Promotion manifest submitted via the Kargo API. No race conditions, non-default configurations, or prior information gathering is required.

Attack Requirements (AT): None

No specific environmental conditions are required beyond a standard Kargo deployment. The http and http-download built-in steps are always available.

Privileges Required (PR): High

The attacker must be authenticated to the Kargo API server and hold permissions sufficient to create or update a Stage, or to craft a Promotion resource directly. Although these may not be considered administrative permissions, they are non-trivial, not granted broadly by default, and must be explicitly assigned by a project administrator.

User Interaction (UI): None

The attack is fully automated via API calls. No other user needs to take any action. The controller processes the malicious Promotion without human intervention.

Confidentiality Impact to Vulnerable System (VC): None

Kargo itself does not expose its own secrets or configuration data through this vulnerability. The impact is to other systems reachable from the controller's network position, not to Kargo's own data.

Integrity Impact to Vulnerable System (VI): None

Kargo's own data and configuration are not modified by this vulnerability. While malicious Promotion resources are created, they function within Kargo's normal processing pipeline.

Availability Impact to Vulnerable System (VA): None

This vulnerability does not enable denial of service against Kargo. Each Promotion executes a bounded set of HTTP requests and does not consume disproportionate resources.

Confidentiality Impact to Subsequent Systems (SC): Low

The controller runs in-cluster and can reach link-local addresses, including cloud instance metadata endpoints. These endpoints are unauthenticated and can expose sensitive data such as IAM credentials. Provider-side header-based SSRF mitigations are ineffective because these steps provide full control over request headers.

Integrity Impact to Subsequent Systems (SI): None

Cloud instance metadata endpoints are read-only. While the http step supports arbitrary HTTP methods, the only unintended access enabled by this vulnerability is to link-local addresses, and these do not accept state-changing requests.

Availability Impact to Subsequent Systems (SA): None

A single HTTP request per promotion step does not constitute a meaningful denial-of-service vector against subsequent systems. There is no amplification mechanism.

Mitigating Factors

  • Exploitation requires authentication to the Kargo API server with permissions to create or update Stages, or to craft Promotion resources directly. These permissions must be explicitly granted by a project administrator.

  • All Promotion creation is audited. The creating user's identity is recorded in annotations and Kubernetes events, providing a clear forensic trail.

  • The practical impact is limited to cloud instance metadata endpoints. Access to private and internal addresses is by design, and services at those addresses are expected to implement their own authentication and authorization.

References

@krancour krancour published to akuity/kargo Mar 14, 2026
Published to the GitHub Advisory Database Mar 16, 2026
Reviewed Mar 16, 2026
Last updated Mar 16, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required High
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality Low
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N

EPSS score

Weaknesses

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-j94x-8wcp-x7hm

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.