CVE-2026-33790

VULNERABILITY OVERVIEW CVE-2026-33790 is an improper input validation vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS running on SRX Series security appliances. The vulnerability exists in the NAT64 translation function, where a specifically crafted malformed ICMPv6 packet destined to the device can trigger a crash of the srxpfe process. The vulnerability affects multiple Junos OS versions ranging from 21.2 through 25.2, with numerous intermediate versions fully unpatched. This issue is exclusive to IPv6 ICMPv6 traffic during NAT64 translation and cannot be triggered via IPv4 or standard IPv6 traffic. SEVERITY ASSESSMENT The vulnerability carries a CVSS 3.1 base score of 7.5 (HIGH) with a network-based attack vector requiring no authentication or user interaction, making it remotely exploitable by any unauthenticated attacker. The impact is limited to availability disruption through repeated process crashes that sustain a denial of service condition, with no confidentiality or integrity compromise. The EPSS score of 0.00055 indicates lower real-world exploitation likelihood compared to other disclosed vulnerabilities, though this does not eliminate the risk to production environments. EXPLOITATION STATUS There is currently no evidence of active exploitation, exploit code availability, or community attention to this vulnerability. The CVE does not appear on the Known Exploited Vulnerabilities (KEV) catalog, and the vulnerability remains inactive on industry hotlists. Organizations should apply available patches across affected Junos OS versions as part of standard vulnerability management practices.