Junos OS (SRX firewalls)
CVE-2025-52955: When jflow/sflow is configured continuous logical interface flaps causes rpd crash and restart
An Incorrect Calculation of Buffer Size vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a memory corruption that leads to a rpd crash.
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 0 | 21.2R3-S9 or later |
| Junos OS 21.4 | 21.4* or later |
| Junos OS 22.2 | 22.2* or later |
| Junos OS 22.4 | 22.4R3-S7 or later |
| Junos OS 23.2 | 23.2R2-S3 or later |
| Junos OS 23.4 | 23.4R2-S4 or later |
| Junos OS 24.2 | 24.2R2 or later |
| Junos OS Evolved 0 | 21.2*-EVO or later |
| Junos OS Evolved 21.4 | 21.4*-EVO or later |
| Junos OS Evolved 22.2 | 22.2*-EVO or later |
| Junos OS Evolved 22.4 | 22.4R3-S7-EVO or later |
| Junos OS Evolved 23.2 | 23.2R2-S3-EVO or later |
| Junos OS Evolved 23.4 | 23.4R2-S4-EVO or later |
| Junos OS Evolved 24.2 | 24.2R2-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Incorrect Calculation of Buffer Size vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a memory corruption that leads to a rpd crash.
When the logical interface using a routing instance flaps continuously, specific updates are sent to the jflow/sflow modules. This results in memory corruption, leading to an rpd crash and restart.
Continued receipt of these specific updates will cause a sustained Denial of Service condition.
This issue affects Junos OS:
- All versions before 21.2R3-S9,
- All versions of 21.4,
- All versions of 22.2,
- from 22.4 before 22.4R3-S7,
- from 23.2 before 23.2R2-S3,
- from 23.4 before 23.4R2-S4,
- from 24.2 before 24.2R2.
Junos OS Evolved:
- All versions of 21.2-EVO,
- All versions of 21.4-EVO,
- All versions of 22.2-EVO,
- from 22.4 before 22.4R3-S7-EVO,
- from 23.2 before 23.2R2-S3-EVO,
- from 23.4 before 23.4R2-S4-EVO,
- from 24.2 before 24.2R2-EVO.
Am I affected?
This issue only happens when jflow is configured:
[services flow-monitoring (version-ipfix|version9)]
Workarounds
Limit CLI access to trusted users shall avoid this situation
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.