External risk intelligence

Cronicle Event Parameter Injection Leading to Privilege Escalation

CVE advisorySeverity: CRITICAL (CVSS 9.0)

CVE-2026-85076

Cronicle is a multi-server task scheduler that includes a web-based front-end UI. Such applications are commonly deployed as network-accessible management interfaces or scheduling dashboards, making them reachable via web browsers by authenticated users. Because the web UI is a primary interface for interaction and configuration, it is often exposed to the network.

Privilege Escalation

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability exists in Cronicle, a task scheduling system, that could allow an authenticated user to potentially escalate privileges or execute arbitrary code by supplying improperly handled parameters. This could lead to unauthorized access to data or disruptions in service.

Issue: Unchecked input in task scheduling can lead to system compromise.
Leadership concern: Potential for unauthorized code execution and data access.
Executive takeaway: Confirm if Cronicle is used and assess associated risks.

Attack Path

How an attacker could exploit the issue

An attacker with existing authenticated access and specific privileges on Cronicle can exploit a flaw in how event parameters are handled. By supplying undeclared keys in API requests, they can manipulate environment variables used by child processes. This manipulation can lead to a complete compromise of the system, including unauthorized code execution, data access, or service disruption, depending on the installed plugins.

Authenticated non-admin user.
Supplying undeclared keys in API calls.
Privilege escalation, code execution, data access.

Live Threat

Current exploitation, exposure, and threat context

An authenticated non-administrator user with specific privileges could supply undeclared keys in event parameters to the API. This could lead to the uppercasing of these keys and their application to the child process environment, potentially overriding plugin variables and causing privilege escalation, arbitrary code execution, data access, or service disruption when supported by the plugin and runtime.

System and user data could be affected.
Exploitation could occur via API calls.
Consequences may include code execution and data access.

Operational Fix

Recommended remediation, mitigation, and detection steps

The platform or infrastructure team responsible for Cronicle deployments should lead the response, coordinating with application owners if Cronicle is embedded within specific applications. The immediate practical step is to locate all Cronicle instances, assess their network exposure and business criticality, and identify the specific owners for each instance to plan remediation based on assessed risk.

Platform teams own the issue.
Verify Cronicle instance exposure.
Plan risk-based remediation.

Supplementary metadata

CVSS vector

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Frequently asked questions

What is Cronicle?

Cronicle is a task scheduler and runner designed for multi-server environments. It provides a web-based dashboard that allows teams to automate, manage, and monitor background tasks or jobs across an entire infrastructure, serving as a central hub for orchestration.

What is the vulnerability in CVE-2026-85076?

This flaw involves Improper Neutralization of Special Elements (CWE-74) and Incorrect Authorization (CWE-863). The system fails to validate event parameters, allowing a user to inject unexpected keys. These keys are then applied to the environment of child processes, potentially overriding security settings and leading to unauthorized control.

How does an attacker trigger this issue?

An authenticated user with non-admin event privileges (like create or run) must submit a crafted API request with unauthorized parameters. Merely viewing the UI or having an account without these specific event-management permissions does not trigger the vulnerability, as the injection requires interacting with the specific event API endpoints.

Is my Cronicle instance at risk?

Halo Surface Signal indicates that because Cronicle functions as a network-accessible dashboard, it is often exposed to the network. If your instance is reachable by authenticated users over the network, it is a primary target. Even internal-only deployments are vulnerable if an attacker gains standard user-level access.

What should I do to secure my deployment?

First, identify all running Cronicle instances and verify their version numbers. If you are running anything below version 0.9.124, prioritize an update immediately to incorporate the parameter validation fixes. Coordinate with your platform teams to assess the criticality and network reach of each instance while planning the rollout.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.