Critical XXE Vulnerability Discovered in Apache Syncope IAM Platform
Apache Syncope, a widely used open-source identity and access management (IAM) solution, has disclosed a critical XML External Entity (XXE) vulnerability in its Console component. Tracked as CVE-2026-23795, the flaw allows authenticated administrators to execute XXE attacks, potentially extracting sensitive data from affected systems.
The vulnerability was discovered by security researchers Follycat and Y0n3er and stems from improper restrictions on XML External Entity references in the Syncope Console. Exploiting this flaw, attackers with administrative access can craft malicious XML payloads via Keymaster parameters, enabling unauthorized file reads, internal system access, and potential privilege escalation within IAM infrastructure.
The issue affects Apache Syncope versions 3.0–3.0.15 and 4.0–4.0.3, impacting thousands of global deployments. Given the platform’s role in managing authentication and authorization, compromised session tokens could grant attackers access to user accounts and sensitive organizational resources.
Apache has released patched versions (3.0.16 and 4.0.4) that implement hardened XML parsing to mitigate the risk. Organizations are advised to upgrade immediately to prevent exploitation. The vulnerability underscores the importance of securing administrative access in IAM environments, where misconfigurations can lead to severe data breaches.
Source: https://cyberpress.org/apache-syncope-vulnerability-2/
The Apache Software Foundation cybersecurity rating report: https://www.rankiteo.com/company/the-apache-software-foundation
"id": "THE1770108756",
"linkid": "the-apache-software-foundation",
"type": "Vulnerability",
"date": "2/2026",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'customers_affected': 'Thousands of global deployments',
'industry': 'Identity and Access Management (IAM)',
'location': 'Global',
'name': 'Apache Syncope',
'type': 'Open-source software'}],
'attack_vector': 'Authenticated administrative access via malicious XML '
'payloads',
'data_breach': {'data_exfiltration': 'Potential (via XXE attacks)',
'personally_identifiable_information': 'Potential (user '
'accounts, session '
'tokens)',
'sensitivity_of_data': 'High',
'type_of_data_compromised': 'Sensitive data, session tokens, '
'user accounts, organizational '
'resources'},
'description': 'Apache Syncope, a widely used open-source identity and access '
'management (IAM) solution, has disclosed a critical XML '
'External Entity (XXE) vulnerability in its Console component. '
'Tracked as CVE-2026-23795, the flaw allows authenticated '
'administrators to execute XXE attacks, potentially extracting '
'sensitive data from affected systems. The vulnerability stems '
'from improper restrictions on XML External Entity references '
'in the Syncope Console. Exploiting this flaw, attackers with '
'administrative access can craft malicious XML payloads via '
'Keymaster parameters, enabling unauthorized file reads, '
'internal system access, and potential privilege escalation '
'within IAM infrastructure.',
'impact': {'data_compromised': 'Sensitive data extraction, session tokens, '
'user accounts, and organizational resources',
'identity_theft_risk': 'High (due to compromised session tokens '
'and user accounts)',
'operational_impact': 'Potential privilege escalation, '
'unauthorized system access',
'systems_affected': 'Apache Syncope Console (IAM infrastructure)'},
'lessons_learned': 'Importance of securing administrative access in IAM '
'environments and mitigating misconfigurations that can '
'lead to severe data breaches.',
'post_incident_analysis': {'corrective_actions': 'Hardened XML parsing in '
'patched versions (3.0.16 '
'and 4.0.4)',
'root_causes': 'Improper restrictions on XML '
'External Entity references in the '
'Syncope Console'},
'recommendations': 'Organizations should immediately upgrade to patched '
'versions (3.0.16 or 4.0.4) and review administrative '
'access controls in IAM systems.',
'references': [{'source': 'Apache Syncope Security Advisory'},
{'source': 'Security Researchers (Follycat and Y0n3er)'}],
'response': {'containment_measures': 'Patches released (versions 3.0.16 and '
'4.0.4) with hardened XML parsing',
'remediation_measures': 'Upgrade to patched versions (3.0.16 or '
'4.0.4)'},
'title': 'Critical XXE Vulnerability Discovered in Apache Syncope IAM '
'Platform',
'type': 'XXE (XML External Entity) Vulnerability',
'vulnerability_exploited': 'CVE-2026-23795'}