jackson-databind vulnerable to remote code execution due to incorrect deserialization and blocklist bypass

FasterXML jackson-databind through 2.8.10 and 2.9.x through 2.9.3 allows unauthenticated remote code execution because of an incomplete fix for the CVE-2017-7525 deserialization flaw. This is exploitable by sending maliciously crafted JSON input to the readValue method of the ObjectMapper, bypassing a blacklist that is ineffective if the Spring libraries are available in the classpath.