CVE-2025-60011: Junos OS and Junos OS Evolved: Optional transitive BGP attribute is modified before propagation to peers causing sessions to flap

Severity: medium (CVSS 5.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-15 · updated 2026-06-17
Weakness: CWE-754

Description

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: * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5 * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S2, * 24.4 versions before 24.4R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-S6-EVO, * 24.2 versions before 24.2R2-S2-EVO, * 24.4 versions before 24.4R2-EVO.

Affected products

Juniper Junos OS: before 22.4; 22.4, 22.4-r1, 22.4-r1-s1, 22.4-r1-s2, 22.4-r2, 22.4-r2-s1 (+38) — fixed in 22.4
Juniper Networks Junos OS Evolved: before 22.4; 22.4, 22.4-r1, 22.4-r1-s1, 22.4-r1-s2, 22.4-r2, 22.4-r2-s1 (+37) — fixed in 22.4

How to fix

Upgrade to a fixed version: Juniper Junos OS 22.4; Juniper Networks Junos OS Evolved 22.4. Check the vendor advisory for mitigations.

References

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