Patch Redash 26.0-9.0 to stop DuckDB flaws from leaking secrets and enabling full system compromise

Redash, a data visualization and sharing package, contains a critical security flaw that allows unauthorized file access. The vulnerability exists in versions from 26.0.0 up to 26.9.0, according to the National Vulnerability Database record for CVE-2026-77371. This issue enables users with query access to interact with the local file system in ways that were not intended by the software design.

The flaw carries a CVSS score of 9.3, rated as critical. It stems from how the DuckDB query runner handles connections in the redash/query_runner/duckdb.py file. Specifically, the _connect() path creates connections with enable_external_access left at its default value of true. This configuration mistake exposes the underlying file system to anyone who can execute queries against an administrator-created DuckDB data source.

How the flaw works

An attacker needs only query access to a DuckDB data source created by an administrator. Once connected, they can use native file-reading functions to retrieve any files that the Redash process can read. Alternatively, they can use the COPY TO command to write new files with the same privileges as the Redash process. This capability turns a data visualization tool into a vector for local file system manipulation without requiring direct server access.

Who is affected

Any organization running Redash versions 26.0.0 through 26.9.0 is vulnerable. The impact is particularly severe because attackers can read sensitive application secrets. These include REDASH_COOKIE_SECRET and REDASH_SECRET_KEY. If an attacker retrieves these secrets, they can forge sessions and bypass authentication mechanisms. This effectively grants them unauthorized access to the application as if they were legitimate users.

What to watch

The vendor has released a fix for this issue in version 26.9.0. Organizations should verify their current Redash version immediately. Those running affected versions should plan to upgrade to 26.9.0 or later to close this gap. Until the update is applied, the risk remains active for any user with query access to DuckDB data sources.

What made it possible

This incident illustrates the risk of default-enabled external access in database connectors. Teams usually assume that query runners are isolated from the host file system. When a connector allows external access by default, it creates a path for privilege escalation. Attackers exploit this by reading configuration files or writing executable scripts. This stage of an intrusion serves as an initial foothold, allowing lateral movement or credential theft. Check whether your database connectors restrict file system access to only necessary directories.

Background: Lateral movement

Lateral movement is the process where an attacker navigates through a network after initial access. They move from one system to another to reach high-value targets. This tactic exploits trust relationships and weak internal controls. Understanding this meaning helps you secure internal pathways, not just the outer gate.

Read the full guide: Lateral Movement Meaning: How Attackers Spread Inside Your Network

What to do and how to stay safe: Redash

• Verify your current Redash version and upgrade to 26.9.0 or later to apply the vendor's fix.
• Audit all DuckDB data sources to ensure they are created only by trusted administrators.
• Monitor logs for unusual file read or write operations originating from the Redash process.
• Review access controls to limit which users have query access to external data sources.

Step-by-step guide: Stop Privilege Escalation: 5 Actions to Block Local Attacks

General security guidance from the Shell Bulletin newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

Which Redash versions are vulnerable to CVE-2026-77371?

Versions from 26.0.0 up to, but not including, 26.9.0 are affected by this critical vulnerability.

What can an attacker do with this flaw?

An attacker can read local files or write new files using the Redash process's privileges, potentially stealing secrets.

Is there a fix available for this issue?

Yes, the issue is fixed in Redash version 26.9.0, according to the National Vulnerability Database record.