CVE-2021-39923: Debian Linux

High severity, CVSS 7.5. EPSS: 1.6% chance of exploitation in the next 30 days.

Large loop in the PNRP dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only; version 9.0 only
• Wireshark Wireshark: from 3.2.0, up to and including 3.2.17; from 3.4.0, up to and including 3.4.9

Published 2021-11-19. Last modified 2026-06-17.