CVE-2026-56446: Authenticated Remote Code Execution via Arbitrary NDJSON Error Log Path in MISP
MISP allowed a site administrator to configure an arbitrary filesystem path for the NDJSON error log used by JsonLogTool. Because log entries can include attacker-controlled content, an authenticated attacker with site administrator privileges could direct log output to a PHP file in a web-accessible directory and inject PHP code through logged data. Accessing the resulting file could lead to remote code execution with the privileges of the web server process.
The fix restricts log destinations to existing directories beneath APP/tmp/logs or /var/log, requires absolute paths, rejects stream wrappers and traversal-related input, and limits filenames to .log or .ndjson extensions while disallowing executable extension segments.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Restrict NDJSON log destinations to existing directories beneath APP/tmp/logs or /var/log.
MISP JsonLogTool NDJSON error log destination allowed_directories = existing directories beneath APP/tmp/logs or /var/log - Configuration
Require absolute paths for NDJSON error log destinations (do not accept relative paths).
MISP JsonLogTool NDJSON error log destination path_format = absolute path required - Configuration
Limit NDJSON error log filenames to .log or .ndjson extensions and disallow executable extension segments.
MISP JsonLogTool NDJSON error log filename filename_extensions = .log or .ndjson; disallow executable extension segments - Configuration
Reject stream wrappers and any traversal-related input when accepting NDJSON error log paths.
MISP JsonLogTool NDJSON error log input validation reject_stream_wrappers_and_traversal = reject stream wrappers and traversal-related input
Event History
Frequently Asked Questions
What is the severity of CVE-2026-56446?
The severity of CVE-2026-56446 is rated high with a score of 8.7 on the CVSS scale.
How does CVE-2026-56446 allow an attacker to execute code?
CVE-2026-56446 allows an authenticated attacker with site administrator privileges to direct NDJSON error log output to a PHP file, enabling remote code execution.
Who is affected by CVE-2026-56446?
CVE-2026-56446 affects installations of MISP where site administrators have the capability to configure arbitrary paths for the NDJSON error log.
What is the recommended fix for CVE-2026-56446?
The recommended fix for CVE-2026-56446 is to update MISP to the latest version that patches this vulnerability.
What type of injection does CVE-2026-56446 involve?
CVE-2026-56446 involves code injection due to the ability to manipulate log entries with attacker-controlled content.