CVE-2021-39194

Public Exploit
Denial of service while parsing polymorphic input with tagged polymorphism style in kaml

Description

kaml is an open source implementation of the YAML format with support for kotlinx.serialization. In affected versions 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. Version 0.35.3 or later contain the fix for this issue.

Category

4.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.48%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: charleskorn kaml
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-39194?
CVE-2021-39194 has been scored as a medium severity vulnerability.
How to fix CVE-2021-39194?
To fix CVE-2021-39194, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-39194 being actively exploited in the wild?
It is possible that CVE-2021-39194 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-39194?
CVE-2021-39194 affects charleskorn kaml.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.