PT-2026-56974 · Juniper Networks · Junos

Published

2026-07-09

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Updated

2026-07-09

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CVE-2026-57020

CVSS v3.1

6.5

Medium

VectorAV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on QFX10000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).
On all QFX10000 platforms in an EVPN-VxLAN scenario, if an attacker sends IPv6 multicast traffic and these packets reach the non-IRB interface of a spine switch it floods the packet to other spines and all Ethernet Segment Identifier (ESI) leaf switches. This flooding causes the packet to be forwarded in a endless loop, which can lead to saturation of the involved links and in turn impact to legitimate traffic.
This issue affects Junos OS on QFX10000 Series:
  • all versions before 23.2R2-S7,
  • 23.4 versions before 23.4R2-S8,
  • 24.2 versions before 24.2R2-S4,
  • 24.4 versions before 24.4R2-S4.
This issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.

Fix

Improper Check for Exceptional Conditions

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Weakness Enumeration

Related Identifiers

CVE-2026-57020

Affected Products

Junos