Junos OS (SRX firewalls)
CVE-2025-52981: SRX Series: Sequence of specific PIM packets causes a flowd crash
An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX1600, SRX2300, SRX 4000 Series, and SRX5000 Series with SPC3 allows an unauthenticated, network-based attacker to cause 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-S11 or later |
| Junos OS (SRX Series) 22.2 | 22.2R3-S7 or later |
| Junos OS (SRX Series) 22.4 | 22.4R3-S6 or later |
| Junos OS (SRX Series) 23.2 | 23.2R2-S4 or later |
| Junos OS (SRX Series) 23.4 | 23.4R2-S4 or later |
| Junos OS (SRX Series) 24.2 | 24.2R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Improper Check for Unusual or Exceptional Conditions vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on
SRX1600, SRX2300, SRX 4000 Series, and SRX5000 Series with SPC3
allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
If a sequence of specific PIM packets is received, this will cause a flowd crash and restart.
This issue affects Junos OS:
- all versions before 21.2R3-S9,
- 21.4 versions before 21.4R3-S11,
- 22.2 versions before 22.2R3-S7,
- 22.4 versions before 22.4R3-S6,
- 23.2 versions before 23.2R2-S4,
- 23.4 versions before 23.4R2-S4,
- 24.2 versions before 24.2R2.
This is a similar, but different vulnerability than the issue reported as
CVE-2024-47503, published in JSA88133.
Workarounds
Minimize the PIM (Protocol Independent Multicast) session timeout value to be less than 5 seconds to avoid data session creation errors.
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.