CVE-2026-47856: CWE-502 Deserialization of Untrusted Data in Spring Spring Integration

Spring Integration's JSON to object conversion mechanism uses the json__TypeId__ header to determine the target deserialization class. This header value is resolved using ClassUtils.forName without enforcing any type or package allow-list, leading to unsafe deserialization of untrusted data. This flaw affects Spring Integration versions 5.5.21 and earlier, 6.4.0 through 6.4.12, 6.5.0 through 6.5.10, 7.0.0 through 7.0.5, and 7.1.0. The vulnerability is identified as CWE-502 and has a CVSS 3.1 base score of 6.3, indicating medium severity. There is no vendor advisory or patch information available at this time.

Successful exploitation could allow an attacker with low privileges and no user interaction to cause limited confidentiality, integrity, and availability impacts due to unsafe deserialization of untrusted data. The CVSS vector indicates network attack vector, low attack complexity, and partial impacts on confidentiality, integrity, and availability.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider mitigating risks by restricting or validating the json__TypeId__ header input if possible, or applying custom deserialization filters. Monitor official Spring advisories for updates.