CVE-2026-77051: Apache Syncope SQL Injection Vulnerability

CVE-2026-77051 Overview

CVE-2026-77051 is an SQL Injection vulnerability in Apache Syncope, an open-source identity management system. An authenticated administrator with sufficient entitlements can execute arbitrary SQL through stacked queries by abusing unsanitized entityKey and opEvent parameters. The flaw affects Apache Syncope 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. The Apache Syncope project has released versions 4.0.8 and 4.1.3 to remediate the issue. The vulnerability is classified under CWE-89.

Critical Impact
Successful exploitation allows arbitrary SQL execution against the Syncope backend, enabling full compromise of identity data, credentials, and workflow integrity.

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-2026-77051 published to NVD
2026-09-14 - Last updated in NVD database

Technical Details for CVE-2026-77051

Vulnerability Analysis

Apache Syncope exposes administrative endpoints that accept entityKey and opEvent parameters. These parameters flow into database queries without proper neutralization of special SQL characters. Because the backend driver processes stacked queries, an attacker can terminate the intended statement and append additional SQL commands in the same request.

Exploitation requires an authenticated administrator account with adequate entitlements. Once achieved, attackers can read, modify, or destroy identity records, escalate privileges within the Syncope realm, and pivot into connected downstream systems such as LDAP directories or provisioned applications.

Root Cause

The root cause is missing input sanitization on the entityKey and opEvent parameters before their concatenation into SQL queries. The absence of parameterized queries in the affected code paths allows attacker-controlled input to alter query structure, satisfying the conditions for classic SQL injection under CWE-89.

Attack Vector

The attack is network-reachable and requires authentication as a Syncope administrator with the entitlements needed to invoke the vulnerable endpoints. The attacker submits crafted values in entityKey or opEvent that contain SQL statement terminators followed by additional queries. Because stacked queries are executed, the injected SQL runs with the database privileges granted to the Syncope service account.

Refer to the Apache Mailing List Update and the Openwall OSS Security Discussion for coordinated disclosure details.

Detection Methods for CVE-2026-77051

Indicators of Compromise

Requests to Syncope administrative APIs containing SQL metacharacters such as ;, --, /*, or UNION inside the entityKey or opEvent parameters.
Unexpected database sessions originating from the Syncope service account executing DDL or multi-statement DML.
Audit log entries showing administrator actions with malformed or oversized entityKey or opEvent values.

Detection Strategies

Enable database query logging on the Syncope datastore and alert on stacked statements originating from application connections.
Deploy a web application firewall rule that inspects requests to Syncope endpoints for SQL injection patterns in the vulnerable parameters.
Review Syncope audit trails for administrator sessions performing atypical entity lookups or event queries.

Monitoring Recommendations

Forward Syncope application logs and backend database audit logs to a central analytics platform for correlation.
Baseline normal administrator query patterns and alert on deviations such as bursts of failed queries or unusual query structures.
Monitor for creation of new administrator accounts or entitlement changes immediately following suspicious API calls.

How to Mitigate CVE-2026-77051

Immediate Actions Required

Upgrade Apache Syncope to version 4.0.8 or 4.1.3 without delay. Users of the 3.0.x branch should plan migration to a fixed branch since no fixed 3.0.x release is listed in the advisory.
Rotate credentials for administrator accounts and for the database service account used by Syncope after patching.
Audit administrator activity logs for the presence of stacked query patterns during the exposure window.

Patch Information

The Apache Syncope project fixed the SQL injection in versions 4.0.8 and 4.1.3. Upgrade guidance is published in the Apache Mailing List Update.

Workarounds

Restrict administrative console and API access to a trusted management network segment using network access controls.
Reduce administrator entitlements to the minimum required, limiting the population of accounts that could invoke the vulnerable endpoints.
Configure the Syncope database user with least privilege, denying DDL and cross-schema access to limit the blast radius of injected SQL.

bash

# Configuration example: restrict database privileges for the Syncope service account
REVOKE ALL PRIVILEGES ON *.* FROM 'syncope'@'%';
GRANT SELECT, INSERT, UPDATE, DELETE ON syncope_db.* TO 'syncope'@'app-subnet';
FLUSH PRIVILEGES;