CVE-2026-25211: Llama Stack Information Disclosure Flaw

CVE-2026-25211 Overview

CVE-2026-25211 is an information disclosure vulnerability in Llama Stack (aka llama-stack) before version 0.4.0rc3. The vulnerability occurs because the application fails to censor the pgvector database password when writing to initialization logs, potentially exposing sensitive credentials to unauthorized users with access to log files.

Critical Impact

Database credentials may be exposed in log files, potentially allowing unauthorized access to pgvector database instances if logs are accessible to attackers.

Affected Products

• Llama Stack versions before 0.4.0rc3

Discovery Timeline

• 2026-01-30 - CVE CVE-2026-25211 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-25211

Vulnerability Analysis

This vulnerability is classified under CWE-532 (Insertion of Sensitive Information into Log File). The issue stems from Llama Stack's initialization routine which writes configuration details to log files without properly sanitizing sensitive credential information. When the pgvector database connection is established, the password parameter is included in plain text within the log output.

The local attack vector requires an attacker to have access to the system's log files, which may occur through various means such as shared hosting environments, compromised user accounts with read access to log directories, or through secondary vulnerabilities that expose log contents.

Root Cause

The root cause of this vulnerability is insufficient input sanitization in the logging mechanism during Llama Stack's initialization process. The application directly logs connection parameters including the pgvector password without implementing proper credential masking or redaction. This represents a failure to follow secure coding practices for handling sensitive authentication data in application logs.

Attack Vector

Exploitation of this vulnerability requires local access to the system where Llama Stack is deployed. An attacker would need to:

1. Gain read access to the initialization log files
2. Parse the log entries to extract the exposed pgvector password
3. Use the obtained credentials to access the pgvector database

The fix implemented in version 0.4.0rc3 introduces proper censoring of the password field in log output. Technical details of the patch can be found in GitHub Pull Request #4439.

Detection Methods for CVE-2026-25211

Indicators of Compromise

• Presence of database passwords in plain text within Llama Stack initialization logs
• Unauthorized access attempts to pgvector database instances using credentials that should not be externally known
• Unusual log file access patterns from non-administrative users

Detection Strategies

• Audit Llama Stack log files for any plain text password entries in initialization output
• Monitor file access events on log directories for unauthorized read attempts
• Implement log aggregation with sensitive data detection rules to identify credential exposure

Monitoring Recommendations

• Enable file integrity monitoring on log directories to detect unauthorized access
• Configure alerting for pgvector database authentication failures that may indicate credential misuse
• Review access control lists on log files to ensure only authorized personnel have read permissions

How to Mitigate CVE-2026-25211

Immediate Actions Required

• Upgrade Llama Stack to version 0.4.0rc3 or later immediately
• Review existing log files for exposed credentials and rotate any potentially compromised pgvector passwords
• Restrict file permissions on log directories to minimize unauthorized access risk

Patch Information

The vulnerability has been addressed in Llama Stack version 0.4.0rc3. The fix implements proper credential masking in the initialization logging routine. Organizations should update to this version or later to remediate the vulnerability.

For detailed information about the changes, review the GitHub Comparison between v0.4.0rc2 and v0.4.0rc3 and the associated Pull Request #4439.

Workarounds

• If immediate upgrade is not possible, manually review and purge sensitive credentials from existing log files
• Implement strict file system permissions on log directories to limit read access to essential personnel only
• Consider redirecting initialization logs to a more secure location with enhanced access controls
• Rotate pgvector database credentials after applying the patch to ensure any previously exposed passwords are invalidated