Junos OS (SRX firewalls)
CVE-2025-30645: SRX Series: Transmission of specific control traffic sent out of a DS-Lite tunnel results in flowd crash
A NULL Pointer Dereference vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an attacker causing specific, valid control traffic to be sent out of a Dual-Stack (DS) Lite tunnel to crash the flowd process, resulting in a Denial of Service (DoS).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (SRX Series) 0 | 21.2R3-S9 or later |
| Junos OS (SRX Series) 21.4 | 21.4R3-S9 or later |
| Junos OS (SRX Series) 22.2 | 22.2R3-S5 or later |
| Junos OS (SRX Series) 22.4 | 22.4R3-S6 or later |
| Junos OS (SRX Series) 23.2 | 23.2R2-S3 or later |
| Junos OS (SRX Series) 23.4 | 23.4R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A NULL Pointer Dereference vulnerability in the flow daemon (flowd) of Juniper Networks Junos OS on SRX Series allows an attacker causing specific, valid control traffic to be sent out of a Dual-Stack (DS) Lite tunnel to crash the flowd process, resulting in a Denial of Service (DoS). Continuous triggering of specific control traffic will create a sustained Denial of Service (DoS) condition.
On all SRX platforms, when specific, valid control traffic needs to be sent out of a DS-Lite tunnel, a segmentation fault occurs within the flowd process, resulting in a network outage until the flowd process restarts.
This issue affects Junos OS on SRX Series: * All versions before 21.2R3-S9, * from 21.4 before 21.4R3-S9, * from 22.2 before 22.2R3-S5, * from 22.4 before 22.4R3-S6, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2.
Am I affected?
Exploitation of this issue requires DS-Lite tunneling to be configured on the SRX Series device:
[ security softwires softwire-name <name> softwire-concentrator ...]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.