Apache Syncope CVE-2026-87779

Exploitation requires two concurrent conditions: (1) an AES key of non-standard length (anything other than exactly 16, 24, or 32 bytes) must have been configured in the affected Syncope instance - this is a misconfiguration, not a default deployment state; and (2) the attacker must have read access to Syncope's application log files or a log aggregation system that ingests them. Exploitation is limited by: log access is typically restricted to operators and administrators (not arbitrary remote users); the misconfiguration prerequisite means many correctly-deployed instances are unaffected; and the vulnerability is passive - the key material is only exposed if it was previously logged during a misconfigured startup. The vulnerability does not allow remote code execution, authentication bypass, or exploitation without pre-existing log access.

No CVSS score is provided by NVD; the following is analyst-assessed. The real-world risk hinges on two conditions: (1) the operator must have supplied a non-standard-length AES key, which is a misconfiguration rather than the default, and (2) an adversary must have access to Syncope's application logs. Log access is typically restricted to administrators or log-aggregation-platform readers - not arbitrary network users. The confidentiality impact of the exposed material is high, however: a recovered AES key enables decryption of any data it protects. EPSS data is not available for this CVE, and it is not listed in CISA KEV, consistent with no confirmed active exploitation. The combination of the misconfiguration prerequisite, the log-access requirement, and the absence of a public exploit suggests this is a meaningful but not immediately critical issue for most deployments. The primary real-world risk is insider threat or log exfiltration scenarios where an attacker with partial access (log reader) gains cryptographic material they should not possess.

An administrator configures a 20-byte AES key in Apache Syncope (non-standard length); Syncope silently pads it to 24 bytes and logs the full derived key during startup or configuration reload. A threat actor with read access to the centralized log aggregation platform - such as a SOC analyst, a compromised log shipper, or an insider - extracts the key from the log stream and uses it to decrypt data at rest that Syncope protects with that AES key. No public exploit code has been identified at time of analysis.