CVSS: v3.1: 5.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L)CVSS: v4.0: 6.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M)
An Improper Check for Unusual or Exceptional Conditions vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause an availability impact for downstream devices.
When an affected device receives a specific optional, transitive BGP attribute over an existing BGP session, it will be erroneously modified before propagation to peers. When the attribute is detected as malformed by the peers, these peers will most likely terminate the BGP sessions with the affected devices and thereby cause an availability impact due to the resulting routing churn.
This issue affects:
Junos OS:
Junos OS Evolved:
To be exposed to this issue BGP needs to be configured for at least two peers via:[ protocols bgp ... neighbor ... ]
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
This issue was seen during production usage.
The following software releases have been updated to resolve this specific issue:Junos OS Evolved: 22.4R3-S8-EVO, 23.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S2-EVO, 24.4R2-EVO, 25.2R1-EVO, and all subsequent releases;Junos OS: 22.4R3-S8, 23.2R2-S5, 23.4R2-S6, 24.2R2-S2, 24.4R2, 25.2R1, and all subsequent releases.
This issue is being tracked as 1884492 which is visible on the Customer Support website.
Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).
There are no known workarounds for this issue.
2026-01-14: Initial Publication