In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x DB2 client (vertx-db2-client) contains DRDA protocol handling code that deserializes User Defined Type (UDT) column data using a bare ObjectInputStream.readObject() call with no ObjectInputFilter or class allowlist.
This code path is triggered when a DRDA server sends a result set with a column tagged as UDT (FDOCA protocol LID 0x50). However, DB2 does not support this type of UDT. The FDOCA 0x50 type is never sent by a legitimate DB2 server.
Nevertheless, a malicious or man-in-the-middle DRDA server could craft a response with a 0x50-tagged column, causing the client to deserialize arbitrary attacker-controlled bytes on the Vert.x event loop before any application code can inspect or reject the data. If a Java deserialization gadget chain is present on the application's classpath, this enables remote code execution. Without a gadget chain, denial of service is possible via crafted object graphs. TLS is disabled by default, making man-in-the-middle exploitation feasible.
The impacted component is io.vertx:vertx-db2-client.
{
"cna_assigner": "eclipse",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102469.json"
}{
"extracted_events": [
{
"introduced": "4.0.0"
},
{
"last_affected": "4.5.34"
},
{
"introduced": "5.0.0"
},
{
"last_affected": "5.0.12"
},
{
"introduced": "5.1.0"
},
{
"last_affected": "5.1.9"
},
{
"introduced": "5.2.0"
},
{
"last_affected": "5.2.0"
}
],
"source": "AFFECTED_FIELD"
}