CVE-2026-27877: Grafana Information Disclosure Vulnerability

CVE-2026-27877 Overview

CVE-2026-27877 is a sensitive data exposure vulnerability in Grafana affecting public dashboards with direct data-source configurations. When public dashboards are enabled alongside direct data-sources, all direct data-sources' passwords are exposed to unauthorized users, even when those data-sources are not actively used in the dashboards themselves. This credential leakage can provide attackers with authentication material for backend databases and services connected to Grafana.

Critical Impact

Unauthorized exposure of all direct data-source passwords through public dashboards, potentially compromising backend database credentials and connected services.

Affected Products

• Grafana (multiple versions)
• Grafana deployments using public dashboards with direct data-sources
• Self-hosted and cloud Grafana instances with affected configurations

Discovery Timeline

• 2026-03-27 - CVE CVE-2026-27877 published to NVD
• 2026-03-31 - Last updated in NVD database

Technical Details for CVE-2026-27877

Vulnerability Analysis

This vulnerability represents an information disclosure flaw in Grafana's public dashboard functionality. The core issue stems from improper handling of credential data when public dashboards interact with direct data-source configurations. When a dashboard is made public, the application fails to properly filter or redact sensitive authentication credentials associated with direct data-sources, resulting in password exposure regardless of whether those specific data-sources are utilized by the public dashboard.

The vulnerability requires network access and can be exploited without authentication or user interaction, making it particularly concerning for internet-facing Grafana deployments. Importantly, proxied data-sources are not affected by this vulnerability, as their credential handling follows a different code path that properly protects sensitive information.

Root Cause

The root cause lies in insufficient access control and data filtering within Grafana's public dashboard rendering pipeline. When generating or serving public dashboard content, the application fails to properly segregate and protect direct data-source credentials from unauthorized access. This represents an improper access control issue where sensitive credential information is included in responses or data structures accessible to unauthenticated users viewing public dashboards.

Attack Vector

An attacker can exploit this vulnerability by accessing public dashboards on a vulnerable Grafana instance. The attack does not require authentication, user interaction, or elevated privileges. The attacker simply needs network access to the Grafana instance with public dashboards enabled and direct data-sources configured.

The exploitation path involves:

1. Identifying a Grafana instance with public dashboards enabled
2. Accessing the public dashboard endpoint
3. Extracting exposed direct data-source passwords from the response data
4. Using harvested credentials to access backend databases or services

Since no verified code examples are available for this vulnerability, detailed exploitation mechanics can be found in the Grafana Security Advisory CVE-2026-27877.

Detection Methods for CVE-2026-27877

Indicators of Compromise

• Unusual or unauthorized access patterns to public dashboard endpoints
• Unexpected authentication attempts to backend data-sources from external IP addresses
• Access logs showing credential extraction attempts against Grafana API endpoints
• Anomalous queries or connections to databases using credentials from Grafana data-sources

Detection Strategies

• Monitor Grafana access logs for requests to public dashboard endpoints from suspicious sources
• Implement network-level monitoring for unusual traffic patterns to Grafana instances
• Audit data-source connection logs for authentication attempts using Grafana-configured credentials from unexpected locations
• Deploy web application firewall rules to detect potential credential harvesting attempts

Monitoring Recommendations

• Enable comprehensive logging on Grafana instances, particularly for public dashboard access
• Implement alerting for failed authentication attempts on backend data-sources that may indicate credential theft
• Regularly audit which dashboards are configured as public and which data-sources they can access
• Monitor for configuration changes that enable public dashboards or add direct data-sources

How to Mitigate CVE-2026-27877

Immediate Actions Required

• Convert all direct data-sources to proxied data-sources where possible to eliminate credential exposure
• Review and disable public dashboards that are not strictly necessary
• Audit all direct data-source configurations and rotate any potentially exposed passwords
• Restrict network access to Grafana instances using firewall rules or network segmentation

Patch Information

Grafana has released security updates to address this vulnerability. Organizations should consult the Grafana Security Advisory CVE-2026-27877 for specific patch versions and upgrade instructions. Apply the latest security patches as soon as possible to remediate this vulnerability.

Workarounds

• Convert direct data-sources to proxied data-sources, which are not affected by this vulnerability
• Disable public dashboard functionality until patches can be applied
• Implement network-level access controls to restrict who can access Grafana instances
• Use authentication proxies or VPNs to limit exposure of Grafana to trusted networks only

# Configuration example - Converting to proxied data-sources
# In Grafana data-source configuration, ensure proxy mode is enabled:
# Access: Server (Proxy) instead of Browser (Direct)

# Audit current public dashboards using Grafana CLI
grafana-cli admin data-source-list

# Review Grafana configuration for public dashboard settings
cat /etc/grafana/grafana.ini | grep -A 5 "\[public_dashboards\]"