Use your Snyk tools to find out what libraries are vulnerable and how to what version you need to update.
If this is a transitive (underlying) dependency either update the property of use dependency management like below with snakeyaml.
The properties are defined in the spring-boot-starter-parent
-> spring-boot-dependencies
pom file.
<properties>
...
<snakeyaml.version>2.0</snakeyaml.version>
...
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.yaml</groupId>
<artifactId>snakeyaml</artifactId>
<version>2.0</version>
</dependency>
</dependencies>
</dependencyManagement>