CVE-2021-33056: Linphone Belle-SIP

High severity, CVSS 7.5. EPSS: 1.3% chance of exploitation in the next 30 days.

Belledonne Belle-sip before 4.5.20, as used in Linphone and other products, can crash via an invalid From header in a SIP message.

Affected products

• Linphone Belle-SIP: before 4.5.20 (fixed in 4.5.20)

Published 2021-08-12. Last modified 2026-06-17.