Junos OS (SRX firewalls)
CVE-2025-21600: With certain BGP options enabled, receipt of specifically malformed BGP update causes RPD crash
An Out-of-Bounds Read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer sending a specifically malformed BGP packet to cause rpd to crash and restart, 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 21.4 | 21.4R3-S9 or later |
| Junos OS 22.2 | 22.2R3-S5 or later |
| Junos OS 22.3 | 22.3R3-S4 or later |
| Junos OS 22.4 | 22.4R3-S5 or later |
| Junos OS 23.2 | 23.2R2-S3 or later |
| Junos OS 23.4 | 23.4R2-S3 or later |
| Junos OS 24.2 | 24.2R1-S2, 24.2R2 or later |
| Junos OS 0 | Not affected |
| Junos OS Evolved 21.4-EVO | 21.4R3-S9-EVO or later |
| Junos OS Evolved 22.2-EVO | 22.2R3-S5-EVO or later |
| Junos OS Evolved 22.3-EVO | 22.3R3-S4-EVO or later |
| Junos OS Evolved 22.4-EVO | 22.4R3-S5-EVO or later |
| Junos OS Evolved 23.2-EVO | 23.2R2-S3-EVO or later |
| Junos OS Evolved 23.4-EVO | 23.4R2-S2-EVO or later |
| Junos OS Evolved 24.2-EVO | 24.2R1-S2-EVO, 24.2R2-EVO or later |
| Junos OS Evolved 0 | Not affected |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Out-of-Bounds Read vulnerability in
the routing protocol daemon (rpd) of
Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, logically adjacent BGP peer sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
This issue only affects systems configured in either of two ways:
- systems with BGP traceoptions enabled
* systems with BGP family traffic-engineering (BGP-LS) configured
and can be exploited from a directly connected and configured BGP peer.
This issue affects iBGP and eBGP
with
any address family
configured, and both IPv4 and IPv6 are affected by this vulnerability.
This issue affects:
Junos OS:
*
from 21.4 before 21.4R3-S9, * from 22.2 before 22.2R3-S5, * from 22.3 before 22.3R3-S4, * from 22.4 before 22.4R3-S5, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2-S3, * from 24.2 before 24.2R1-S2, 24.2R2;
Junos OS Evolved:
- from 21.4-EVO before 21.4R3-S9-EVO,
- from 22.2-EVO before 22.2R3-S5-EVO,
- from 22.3-EVO before 22.3R3-S4-EVO,
- from 22.4-EVO before 22.4R3-S5-EVO,
- from 23.2-EVO before 23.2R2-S3-EVO,
- from 23.4-EVO before 23.4R2-S2-EVO,
- from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO.
This issue does not affect versions of Junos OS prior to 21.3R1.
This issue does not affect versions of Junos OS Evolved prior to 21.3R1-EVO.
This is a similar, but different vulnerability than the issue reported as CVE-2024-39516.
Am I affected?
One of the following traceoptions configurations, either at the top level, under [logical-systems], or [routing-instances], is required to be potentially exposed to this issue:
[protocols bgp traceoptions packets detail] [protocols bgp traceoptions update detail] [protocols bgp group <group-name> traceoptions packets detail] [protocols bgp group <group-name> traceoptions update detail] [protocols bgp group <group-name> neighbor <address> traceoptions packets detail] [protocols bgp group <group-name> neighbor <address> traceoptions update detail]
Systems configured with BGP traffic engineering are also vulnerable to this issue:
[protocols bgp group <name> family traffic-engineering unicast]
Workarounds
If BGP traceoptions are enabled, and traffic engineering is not configured, disable BGP traceoptions if they are not being used for active troubleshooting.
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.