CVE-2026-33790 Denial of service in Junos OS
An attacker can cause a denial of service on Juniper SRX devices by sending malformed ICMPv6 packets when NAT64 is configured.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33790?
CVE-2026-33790 is a high-severity denial of service vulnerability in Juniper Junos, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-754
Which versions are affected by CVE-2026-33790?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2026-33790?
No fix has been published for CVE-2026-33790 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-33790 being exploited?
There is no known exploitation of CVE-2026-33790 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-9cqr-g7fq-8jf6.