MongoDB and Ubisoft: Thousands of servers exposed as MongoBleed vulnerability exploited

MongoBleed Vulnerability Exposes Sensitive Data in 87,000 MongoDB Instances

A high-severity vulnerability, MongoBleed (CVE-2025-14847), allows attackers to leak sensitive data from unpatched MongoDB instances by exploiting uninitialized heap memory. The flaw, rated 8.7/10 (high), stems from mismatched length fields in Zlib-compressed protocol headers. By sending a maliciously crafted message, attackers can force the server to allocate an oversized memory buffer, exposing credentials, cloud keys, session tokens, API keys, and other in-memory data—without requiring authentication.

A proof-of-concept (PoC) exploit was published this week by security researcher Joe Desimone, increasing the risk of widespread attacks. According to Censys, approximately 87,000 vulnerable MongoDB instances are exposed online, with the highest concentrations in the U.S. (20,000), China (17,000), and Germany (8,000).

Affected versions include:

• MongoDB 8.2.0–8.2.3, 8.0.0–8.0.16, 7.0.0–7.0.26, 6.0.0–6.0.26, 5.0.0–5.0.31, 4.4.0–4.4.29
• All versions of MongoDB 4.2, 4.0, and 3.6

MongoDB released a patch on December 19, and MongoDB Atlas users were automatically protected. While no confirmed in-the-wild attacks have been reported, researchers have linked the vulnerability to the recent Ubisoft Rainbow Six Siege breach. Organizations running self-hosted instances are advised to apply the fix immediately.

Source: https://www.techradar.com/pro/security/thousands-of-servers-exposed-as-mongobleed-vulnerability-exploited

MongoDB cybersecurity rating report: https://www.rankiteo.com/company/mongodbinc

Ubisoft cybersecurity rating report: https://www.rankiteo.com/company/ubisoft

"id": "MONUBI1767101761",
"linkid": "mongodbinc, ubisoft",
"type": "Vulnerability",
"date": "12/2025",
"severity": "100",
"impact": "5",
"explanation": "Attack threatening the organization's existence"

{'affected_entities': [{'customers_affected': '87,000 exposed instances',
                        'industry': 'Technology',
                        'location': 'Global',
                        'name': 'MongoDB',
                        'type': 'Database Software Provider'},
                       {'industry': 'Entertainment/Gaming',
                        'location': 'Global',
                        'name': 'Ubisoft',
                        'type': 'Gaming Company'}],
 'attack_vector': 'Remote Exploitation',
 'data_breach': {'data_exfiltration': 'Possible via heap memory leak',
                 'sensitivity_of_data': 'High',
                 'type_of_data_compromised': ['Credentials',
                                              'Cloud keys',
                                              'Session tokens',
                                              'API keys',
                                              'Configurations']},
 'date_resolved': '2024-12-19',
 'description': 'MongoBleed is a high-severity vulnerability (CVE-2025-14847) '
                'affecting multiple versions of MongoDB, allowing attackers to '
                'leak sensitive data via uninitialized heap memory '
                'exploitation. A proof-of-concept (PoC) exploit is publicly '
                'available, enabling attackers to send poisoned messages to '
                'vulnerable instances and extract sensitive information such '
                'as credentials, cloud keys, session tokens, and API keys '
                'without requiring valid credentials.',
 'impact': {'data_compromised': 'Credentials, cloud keys, session tokens, API '
                                'keys, configurations, and other sensitive '
                                'data',
            'identity_theft_risk': 'High',
            'systems_affected': 'MongoDB instances (versions 8.2.0-8.2.3, '
                                '8.0.0-8.0.16, 7.0.0-7.0.26, 6.0.0-6.0.26, '
                                '5.0.0-5.0.31, 4.4.0-4.4.29, and all 4.2, 4.0, '
                                'and 3.6 versions)'},
 'investigation_status': 'Ongoing',
 'post_incident_analysis': {'corrective_actions': 'Patch management, '
                                                  'auto-patching for cloud '
                                                  'instances, and public '
                                                  'disclosure of vulnerability '
                                                  'details',
                            'root_causes': 'Mismatched length fields in Zlib '
                                           'compressed protocol headers '
                                           'leading to uninitialized heap '
                                           'memory reads'},
 'recommendations': 'Patch vulnerable MongoDB instances immediately. Monitor '
                    'for unauthorized access or data leaks. Consider network '
                    'segmentation and enhanced monitoring for exposed '
                    'instances.',
 'references': [{'source': 'BleepingComputer'}, {'source': 'TechRadar'}],
 'response': {'containment_measures': 'Patch released for self-hosted '
                                      'instances; MongoDB Atlas auto-patched',
              'remediation_measures': 'Apply patches for vulnerable MongoDB '
                                      'versions'},
 'title': 'MongoBleed (CVE-2025-14847) Data Leak via Uninitialized Heap Memory '
          'Exploitation',
 'type': 'Data Leak',
 'vulnerability_exploited': 'CVE-2025-14847 (Uninitialized heap memory read '
                            'due to mismatched length fields in Zlib '
                            'compressed protocol headers)'}