CVE-2026-28280 Overview
CVE-2026-28280 is a stored cross-site scripting (XSS) vulnerability in osctrl, an osquery management solution. The vulnerability exists in the osctrl-admin on-demand query list functionality, allowing attackers with query-level permissions to inject arbitrary JavaScript code via the query parameter. This malicious payload is stored and subsequently executes in the browser of any user—including administrators—who visits the query list page. When combined with CSRF token extraction techniques, this vulnerability can be chained to escalate privileges and perform actions as the authenticated user, potentially leading to full platform compromise.
Critical Impact
An attacker with the lowest privilege tier (query-level permissions) can execute arbitrary JavaScript in the browsers of all users who view the query list. If an administrator's session executes the malicious payload, this can lead to complete platform compromise.
Affected Products
- osctrl versions prior to 0.5.0
- osctrl-admin component (on-demand query list feature)
Discovery Timeline
- 2026-02-26 - CVE-2026-28280 published to NVD
- 2026-02-26 - Last updated in NVD database
Technical Details for CVE-2026-28280
Vulnerability Analysis
This stored XSS vulnerability (CWE-79) arises from improper input validation and output encoding in the osctrl-admin web interface. When a user with query-level permissions submits an on-demand query, the application fails to properly sanitize the query parameter input before storing it in the database. Subsequently, when any user navigates to the query list page, the stored malicious payload is rendered without proper encoding, causing the injected JavaScript to execute within the victim's browser context.
The vulnerability is particularly concerning because query-level permissions represent the lowest privilege tier in osctrl's access control model. This means even users with minimal access rights can inject persistent malicious scripts that target all other users of the platform, including those with administrative privileges.
Root Cause
The root cause of this vulnerability is the lack of proper input sanitization on the query parameter during submission and insufficient output encoding when rendering stored queries on the query list page. The application trusts user-supplied input and reflects it directly into the HTML response without applying context-appropriate encoding, creating a classic stored XSS condition.
Attack Vector
The attack vector is network-based and requires the attacker to have authenticated access with at least query-level permissions. The attack unfolds in the following sequence:
- An attacker with query-level permissions crafts a malicious on-demand query containing JavaScript code within the query parameter
- The malicious payload is submitted through the osctrl-admin interface and stored in the application database
- When any authenticated user (including administrators) visits the query list page, the stored payload executes in their browser
- The attacker can chain this with CSRF token extraction to perform privileged actions as the victim user
- If an administrator triggers the payload, the attacker can potentially create new admin accounts or modify system configurations
The vulnerability does not require user interaction beyond the victim visiting the query list page, which is a common administrative action in osctrl deployments.
Detection Methods for CVE-2026-28280
Indicators of Compromise
- Unusual JavaScript code patterns in query list entries (e.g., <script> tags, event handlers like onerror, onload)
- Queries containing encoded script payloads or obfuscated JavaScript
- Unexpected administrator account creation or privilege escalation events
- Anomalous API calls or configuration changes following query list page visits
Detection Strategies
- Implement web application firewall (WAF) rules to detect and block XSS payloads in query submissions
- Monitor application logs for queries containing HTML tags or JavaScript event handlers
- Deploy browser-based XSS detection extensions for security team browsers
- Review database records in the query storage tables for suspicious content patterns
Monitoring Recommendations
- Enable detailed logging for all query submission and modification events
- Configure alerts for new administrator account creation or privilege changes
- Monitor for unusual session activity following query list page access
- Implement Content Security Policy (CSP) headers to restrict inline script execution
How to Mitigate CVE-2026-28280
Immediate Actions Required
- Upgrade osctrl to version 0.5.0 or later immediately
- Audit existing query list entries for potentially malicious payloads
- Review osctrl user accounts for any unauthorized administrators that may have been created through exploitation
- Restrict query-level permissions to trusted users only until patching is complete
Patch Information
The vulnerability is fixed in osctrl version 0.5.0. The fix was implemented through two pull requests that address the input validation and output encoding issues:
For complete details on the vulnerability and remediation, refer to the GitHub Security Advisory GHSA-4rv8-5cmm-2r22.
Workarounds
- Restrict query-level permissions to only trusted users within the organization
- Manually monitor the query list for suspicious payloads containing script tags or JavaScript code
- Conduct a security review of osctrl user accounts to identify and remove unauthorized administrators
- Implement Content Security Policy headers to mitigate the impact of any injected scripts
- Consider temporarily disabling the on-demand query feature until patching is complete
# Upgrade osctrl to the patched version
# Pull the latest release from the official repository
git fetch --tags
git checkout v0.5.0
# Rebuild and redeploy osctrl-admin
make build
# Follow your deployment process to update the running instance
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
