CVE-2026-33790: Juniper Junos

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an attacker sending a specific, malformed ICMPv6 packet to cause the srxpfe process to crash and restart. Continued receipt and processing of these packets will repeatedly crash the srxpfe process and sustain the Denial of Service (DoS) condition. During NAT64 translation, receipt of a specific, malformed ICMPv6 packet destined to the device will cause the srxpfe process to crash and restart. This issue cannot be triggered using IPv4 nor other IPv6 traffic. This issue affects Junos OS on SRX Series: * all versions before 21.2R3-S10, * all versions of 21.3, * from 21.4 before 21.4R3-S12, * all versions of 22.1, * from 22.2 before 22.2R3-S8, * all versions of 22.4, * from 22.4 before 22.4R3-S9, * from 23.2 before 23.2R2-S6, * from 23.4 before 23.4R2-S7, * from 24.2 before 24.2R2-S3, * from 24.4 before 24.4R2-S3, * from 25.2 before 25.2R1-S2, 25.2R2.

Affected products

• Juniper Junos: before 21.2 (fixed in 21.2); version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; version 22.2 only; …

Published 2026-04-09. Last modified 2026-06-17.