CVE-2021-39194

Name of the Vulnerable Software and Affected Versions kaml versions prior to 0.35.3

Description Attackers that could provide arbitrary YAML input to an application that uses kaml could cause the application to endlessly loop while parsing the input. This could result in resource starvation and denial of service. This only affects applications that use polymorphic serialization with the default tagged polymorphism style. Applications using the property polymorphism style are not affected. YAML input for a polymorphic type that provided a tag but no value for the object would trigger the issue, for example, !<x>.

Recommendations For versions prior to 0.35.3, update to version 0.35.3 or later to resolve the issue. As a temporary workaround, consider avoiding the use of polymorphic serialization with the default tagged polymorphism style until a patch is applied. Restrict access to YAML input to minimize the risk of exploitation.