Deserialization of Untrusted Data in jackson-databind - CVE-2026-54512
Published: July 22, 2026
Vulnerability identifier: #VU139159
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-54512
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: FasterXML
Affected software:
jackson-databind
jackson-databind
Detailed vulnerability description
The vulnerability allows a remote attacker to instantiate arbitrary classes.
The vulnerability exists due to deserialization of untrusted data in DatabindContext._resolveAndValidateGeneric() and PolymorphicTypeValidator handling when processing polymorphic type identifiers with generic parameters during deserialization. A remote attacker can supply a specially crafted type identifier and JSON data to instantiate arbitrary classes.
Only applications that accept untrusted JSON and have polymorphic typing enabled while relying on a configured PolymorphicTypeValidator allow-list are affected.
How to mitigate CVE-2026-54512
Install security update from vendor's website.