CVE-2026-40584 Overview
CVE-2026-40584 is an Information Disclosure vulnerability affecting RansomLook, a tool used to monitor ransomware groups and markets. The vulnerability exists in the API component within website/web/api/genericapi.py, where improper filtering of private location entries allows unauthorized disclosure of non-public location information. The flaw stems from incorrect list iteration logic that fails to properly remove private entries from API responses.
Critical Impact
Unauthorized disclosure of private location information through API responses, potentially exposing sensitive data about monitored ransomware group activities.
Affected Products
- RansomLook versions prior to 1.9.0
Discovery Timeline
- 2026-04-21 - CVE-2026-40584 published to NVD
- 2026-04-22 - Last updated in NVD database
Technical Details for CVE-2026-40584
Vulnerability Analysis
This vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor). The flaw occurs in the API endpoint handling within genericapi.py where the application attempts to filter out private location entries before returning data to API consumers. Due to a programming error in the list iteration logic, elements marked as private may be unintentionally retained in API responses.
The core issue relates to modifying a list while iterating over it—a common programming mistake in Python that leads to skipped elements. When the code encounters a private entry and removes it from the list, the iterator's position becomes misaligned with the actual list indices, causing subsequent private entries to be skipped during the filtering process.
Root Cause
The root cause is improper list manipulation during iteration in Python. When removing elements from a list while iterating over it with a standard for loop, the list indices shift, causing the iterator to skip elements. This results in some private location entries being unintentionally retained in the API response data.
The correct approach would involve either iterating over a copy of the list, building a new filtered list, or iterating in reverse order when removing elements. The fix in version 1.9.0 addresses this logic error to ensure all private entries are properly filtered.
Attack Vector
The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker can send requests to the affected API endpoint and receive responses that may contain private location information that should have been filtered out.
The attack requires no special privileges or complex conditions—a simple API request to the affected endpoint is sufficient to potentially retrieve private data. The impact is limited to confidentiality, as the vulnerability only allows reading of information that should be private; it does not enable modification or destruction of data.
Detection Methods for CVE-2026-40584
Indicators of Compromise
- Unusual or unexpected API requests targeting RansomLook location endpoints
- API responses containing location data marked with private flags
- Increased query volume from unknown sources targeting the genericapi.py endpoints
Detection Strategies
- Monitor API access logs for requests to location-related endpoints from unauthorized sources
- Implement logging for API responses that include location data to detect potential data leakage
- Review audit logs for patterns indicating systematic enumeration of API endpoints
Monitoring Recommendations
- Enable detailed logging on all RansomLook API endpoints
- Set up alerts for abnormal access patterns to the affected API components
- Periodically audit API responses to ensure private data is not being leaked
How to Mitigate CVE-2026-40584
Immediate Actions Required
- Upgrade RansomLook to version 1.9.0 or later immediately
- Review API access logs for any historical exploitation attempts
- Audit any private location data that may have been exposed prior to patching
Patch Information
The vulnerability is fixed in RansomLook version 1.9.0. Organizations should upgrade to this version or later to remediate the vulnerability. Additional details are available in the GitHub Security Advisory and the CIRCL Vulnerability Report.
Workarounds
- Restrict network access to the RansomLook API to trusted sources only until patching is complete
- Implement additional API gateway filtering to validate responses do not contain private location markers
- Consider temporarily disabling the affected API endpoints if they are not critical to operations
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
