CVE-2019-20503 and is rated Medium severity with a CVSS score of 6.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Aug 12, 2026
CBL-Mariner Releases
Vendor-listed releases
0.9.5.0-1
CISA KEVNot listedBased on the latest collected catalog
EPSS3.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2019-20503?
usrsctp before 2019-12-20 has out-of-bounds reads in sctp_load_addresses_from_init.