CVE-2021-27335: Kollectapp Kollect

Critical severity, CVSS 9.8. EPSS: 3% chance of exploitation in the next 30 days.

KollectApps before 4.8.16c is affected by insecure Java deserialization, leading to Remote Code Execution via a ysoserial.payloads.CommonsCollections parameter.

Affected products

• Kollectapp Kollect: before 4.8.16c (fixed in 4.8.16c)

Published 2021-02-18. Last modified 2026-06-17.