CVE-2026-77825 Overview
CVE-2026-77825 is a path traversal vulnerability in IBM ContextForge MCP Gateway versions 1.0.0 through 1.0.8. The flaw exists in the Admin API log-download endpoint GET /v1/admin/logs/file. The endpoint uses Python's str.startswith() to confine file access to the configured LOG_FOLDER instead of performing proper path boundary validation. An authenticated administrator can request .log, .jsonl, or .json files located in sibling directories whose absolute paths share the log directory's string prefix. Successful exploitation discloses the contents of log and JSON files outside the intended directory.
Critical Impact
Authenticated administrators can read arbitrary .log, .jsonl, and .json files outside LOG_FOLDER, potentially exposing sensitive application and system data.
Affected Products
- IBM ContextForge MCP Gateway 1.0.0
- IBM ContextForge MCP Gateway 1.0.1 through 1.0.7
- IBM ContextForge MCP Gateway 1.0.8
Discovery Timeline
- 2026-09-24 - CVE-2026-77825 published to NVD
- 2026-09-29 - Last updated in NVD database
Technical Details for CVE-2026-77825
Vulnerability Analysis
The vulnerability resides in the Admin API handler for GET /v1/admin/logs/file. The handler accepts a filename parameter, resolves it to an absolute path, and then checks whether that absolute path begins with the configured LOG_FOLDER string. Because the comparison uses str.startswith() instead of a path-component boundary check, any sibling directory whose absolute path starts with the same characters as LOG_FOLDER passes validation. For example, if LOG_FOLDER is /var/app/logs, requests resolving to /var/app/logs_backup/secrets.json satisfy the prefix check and are served to the caller. The endpoint restricts returned content to files ending in .log, .jsonl, or .json, which bounds the data categories exposed but does not prevent traversal. The weakness is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory.
Root Cause
The root cause is a flawed path confinement implementation. str.startswith() compares raw character sequences and does not treat directory separators as semantic boundaries. A correct implementation would use pathlib.Path.resolve() combined with is_relative_to() or compare normalized path components. Without that boundary enforcement, sibling directories sharing a common prefix bypass the check.
Attack Vector
Exploitation requires authenticated administrator credentials to the ContextForge MCP Gateway. The attacker issues a crafted GET /v1/admin/logs/file request supplying a filename that resolves to a sibling directory of LOG_FOLDER. The gateway returns the file contents if the extension is .log, .jsonl, or .json. No user interaction and no additional privileges beyond admin API access are required.
No verified exploit code is publicly available. Refer to the IBM Support advisory for vendor technical details.
Detection Methods for CVE-2026-77825
Indicators of Compromise
- Admin API access logs showing GET /v1/admin/logs/file requests with filename parameters containing .., absolute paths, or values that resolve outside the configured LOG_FOLDER.
- Successful 200 responses from the log-download endpoint referencing .json or .jsonl files not generated by the gateway's logging subsystem.
- Unexpected administrator sessions originating from new IP addresses or geolocations.
Detection Strategies
- Enable verbose audit logging on the ContextForge Admin API and alert on log-download requests that include traversal sequences or non-standard filenames.
- Correlate administrator API tokens against expected operator inventory to identify misuse of valid credentials.
- Review file-system access telemetry on the gateway host for reads of .json, .jsonl, or .log files outside LOG_FOLDER performed by the gateway process.
Monitoring Recommendations
- Forward ContextForge access and audit logs to a centralized SIEM for retention and correlation.
- Track rate and volume of /v1/admin/logs/file calls per administrator account and alert on anomalies.
- Monitor outbound data transfers from the gateway host for unusual bursts following admin API activity.
How to Mitigate CVE-2026-77825
Immediate Actions Required
- Upgrade IBM ContextForge MCP Gateway to the fixed release identified in the IBM Support advisory.
- Rotate administrator API tokens and credentials used with vulnerable 1.0.0 through 1.0.8 deployments.
- Audit historical admin API logs for prior exploitation of the /v1/admin/logs/file endpoint.
Patch Information
IBM has published remediation guidance on the vendor support page. Consult the IBM Support advisory for ContextForge for the fixed version and upgrade procedure. Apply the vendor-supplied update to replace the flawed str.startswith() check with proper path boundary validation.
Workarounds
- Restrict network access to the ContextForge Admin API using a reverse proxy or firewall allowlist limited to trusted operator hosts.
- Enforce the principle of least privilege by minimizing the number of accounts holding administrator role on the gateway.
- Relocate LOG_FOLDER to a dedicated directory whose parent contains no sensitive .log, .jsonl, or .json files that share a prefix.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
