CVE-2026-33790: CWE-754 Improper Check for Unusual or Exceptional Conditions in Juniper Networks Junos OS
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.
AI Analysis
Technical Summary
An Improper Check for Unusual or Exceptional Conditions vulnerability (CWE-754) exists in the flow daemon (flowd) of Juniper Networks Junos OS on SRX Series devices. When processing a specific malformed ICMPv6 packet during NAT64 translation, the srxpfe process crashes and restarts repeatedly, causing a Denial of Service (DoS). This affects multiple versions of Junos OS before fixed releases starting from 21.2R3-S10 and continuing through various subsequent versions up to 25.2R2. The vulnerability is exploitable remotely without privileges or user interaction and is limited to ICMPv6 traffic during NAT64 translation. IPv4 and other IPv6 traffic do not trigger this issue. Juniper provides patches and manages remediation for the cloud service environment.
Potential Impact
Successful exploitation causes the srxpfe process on affected Junos OS SRX Series devices to crash and restart repeatedly, resulting in a sustained Denial of Service (DoS) condition. There is no impact on confidentiality or integrity, only availability is affected. The vulnerability can be triggered remotely without authentication or user interaction, making it a significant availability risk for affected network devices.
Mitigation Recommendations
A patch is available for this vulnerability. Juniper Networks manages remediation for this cloud-hosted service, so customers should ensure their Junos OS SRX Series devices are updated to the fixed versions starting from 21.2R3-S10 and later releases as applicable. Check the official Juniper Networks advisory for the latest patch details and upgrade instructions. No additional mitigation is required if the device is updated to a fixed version.
CVE-2026-33790: CWE-754 Improper Check for Unusual or Exceptional Conditions in Juniper Networks Junos OS
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
An Improper Check for Unusual or Exceptional Conditions vulnerability (CWE-754) exists in the flow daemon (flowd) of Juniper Networks Junos OS on SRX Series devices. When processing a specific malformed ICMPv6 packet during NAT64 translation, the srxpfe process crashes and restarts repeatedly, causing a Denial of Service (DoS). This affects multiple versions of Junos OS before fixed releases starting from 21.2R3-S10 and continuing through various subsequent versions up to 25.2R2. The vulnerability is exploitable remotely without privileges or user interaction and is limited to ICMPv6 traffic during NAT64 translation. IPv4 and other IPv6 traffic do not trigger this issue. Juniper provides patches and manages remediation for the cloud service environment.
Potential Impact
Successful exploitation causes the srxpfe process on affected Junos OS SRX Series devices to crash and restart repeatedly, resulting in a sustained Denial of Service (DoS) condition. There is no impact on confidentiality or integrity, only availability is affected. The vulnerability can be triggered remotely without authentication or user interaction, making it a significant availability risk for affected network devices.
Mitigation Recommendations
A patch is available for this vulnerability. Juniper Networks manages remediation for this cloud-hosted service, so customers should ensure their Junos OS SRX Series devices are updated to the fixed versions starting from 21.2R3-S10 and later releases as applicable. Check the official Juniper Networks advisory for the latest patch details and upgrade instructions. No additional mitigation is required if the device is updated to a fixed version.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- juniper
- Date Reserved
- 2026-03-23T19:46:13.672Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
Threat ID: 69d822bf1cc7ad14da2ad16a
Added to database: 4/9/2026, 10:05:51 PM
Last enriched: 4/17/2026, 12:26:32 PM
Last updated: 5/25/2026, 3:14:26 AM
Views: 88
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.