CVE-2021-41110
CVSS v3
9.8
CRITICAL
EPSS Score
2.8 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
cwlviewer is a web application to view and share Common Workflow Language workflows. Versions prior to 1.3.1 contain a Deserialization of Untrusted Data vulnerability. Commit number f6066f09edb70033a2ce80200e9fa9e70a5c29de (dated 2021-09-30) contains a patch. There are no available workarounds aside from installing the patch. The SnakeYaml constructor, by default, allows any data to be parsed. To fix the issue the object needs to be created with a `SafeConstructor` object, as seen in the patch.
Technical details
- Published
- 2021-10-01
Frequently asked questions
What is CVE-2021-41110?
cwlviewer is a web application to view and share Common Workflow Language workflows. Versions prior to 1.3.1 contain a Deserialization of Untrusted Data vulnerability. Commit number f6066f09edb70033a2ce80200e9fa9e70a5c29de (dated 2021-09-30) contains a patch. There are no available workarounds aside from installing the patch. The SnakeYaml constructor, by default, allows any data to be parsed. To fix the issue the object needs to be created with a `SafeConstructor` object, as seen in the patch.
Is CVE-2021-41110 actively exploited?
Active exploitation of CVE-2021-41110 has not been confirmed. Its EPSS score was 2.8% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-41110?
CVE-2021-41110 has a CVSS v3 base score of 9.8 (CRITICAL severity).
Is CVE-2021-41110 affecting your environment?
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