CVE-2026-86460 Overview
CVE-2026-86460 is a Cypher injection vulnerability in the Neo4j persistence layer of Apache Syncope. The flaw occurs when the application processes certain Feed Item Query Language (FIQL) search conditions. Attackers can inject malicious Cypher clauses through crafted FIQL queries, manipulating backend graph database operations without authentication. Apache Syncope versions 3.0.0-M0 through 3.0.16, 4.0.0-M0 through 4.0.7, and 4.1.0-M0 through 4.1.2 are affected. The vulnerability is classified under [CWE-89] (Improper Neutralization of Special Elements used in an SQL Command).
Critical Impact
Unauthenticated attackers can inject arbitrary Cypher queries into the Neo4j backend, exposing identity data, modifying records, and potentially disrupting Syncope-managed identity operations.
Affected Products
- Apache Syncope 3.0.0-M0 through 3.0.16
- Apache Syncope 4.0.0-M0 through 4.0.7
- Apache Syncope 4.1.0-M0 through 4.1.2
Discovery Timeline
- 2026-09-14 - CVE CVE-2026-86460 published to NVD
- 2026-09-14 - Last updated in NVD database
Technical Details for CVE-2026-86460
Vulnerability Analysis
Apache Syncope exposes a FIQL-based search API that translates user-supplied query expressions into backend database operations. When the Neo4j persistence layer is used, these FIQL conditions are converted into Cypher queries. The vulnerability stems from insufficient neutralization of special characters and clauses within specific FIQL search conditions. Attackers who submit crafted search parameters can break out of the intended query context and append arbitrary Cypher statements.
Because the search endpoints are reachable over the network and require no authentication for exploitation, remote attackers can read sensitive identity data, alter user or role records, and interact with the Neo4j graph beyond authorized scope. The impact scales with the sensitivity of the identity data stored by Syncope, which typically includes user accounts, entitlements, and organizational structure.
Root Cause
The root cause is improper input sanitization in the FIQL-to-Cypher translation logic within the Neo4j persistence module. User-controlled values from FIQL search conditions are concatenated into Cypher query strings without adequate parameterization or escaping, allowing injection of Cypher operators and clauses.
Attack Vector
Exploitation requires network access to a Syncope endpoint that accepts FIQL search parameters. The attacker crafts a FIQL expression containing Cypher syntax that terminates the intended query context and appends malicious clauses. No user interaction or privileges are required.
No verified public proof-of-concept code is available. See the Apache Mailing List Thread and OpenWall OSS Security Update for vendor details.
Detection Methods for CVE-2026-86460
Indicators of Compromise
- FIQL search parameters containing Cypher keywords such as MATCH, RETURN, CREATE, DELETE, MERGE, or WITH embedded in request query strings.
- Neo4j query logs showing unexpected multi-statement Cypher execution originating from Syncope service accounts.
- Anomalous read patterns against Neo4j nodes storing user, role, or entitlement data outside normal Syncope workflows.
Detection Strategies
- Inspect HTTP access logs for Syncope search endpoints and flag FIQL expressions containing suspicious characters like ;, backticks, or unescaped braces.
- Enable Neo4j query logging and alert on queries that reference internal labels not typically returned by Syncope search operations.
- Correlate Syncope application logs with Neo4j audit logs to identify request-to-query mismatches indicating injection attempts.
Monitoring Recommendations
- Monitor authentication-free API endpoints in Syncope for spikes in search request volume or error rates.
- Track outbound queries from the Syncope service account against Neo4j baselines and alert on deviations.
- Forward Syncope and Neo4j logs to a centralized analytics platform for correlation and long-term retention.
How to Mitigate CVE-2026-86460
Immediate Actions Required
- Upgrade Apache Syncope to version 4.0.8 or 4.1.3, which contain the vendor fix.
- Restrict network access to Syncope search endpoints to trusted management networks until the upgrade is applied.
- Review Neo4j audit logs for prior injection attempts and validate the integrity of identity records.
Patch Information
The Apache Syncope project released fixed versions 4.0.8 and 4.1.3. Users on the 3.0.x branch should consult the Apache Mailing List Thread for upgrade guidance, as the advisory lists 3.0.0-M0 through 3.0.16 as affected without a corresponding 3.0.x fix version.
Workarounds
- Place a web application firewall in front of Syncope and block FIQL parameters containing Cypher keywords or graph-query metacharacters.
- Disable or gate anonymous search endpoints through reverse proxy authentication until patches are deployed.
- Apply least-privilege database credentials to the Syncope-to-Neo4j connection to limit the blast radius of a successful injection.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
