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CVE-2026-57020

Junos OS: QFX10000 Series: IPv6 multicast traffic received on non-IRB interfaces causes a multicast flood

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 23.2R2-S7, 23.4R2-S8, 24.2R2-S4, 24.4R2-S4
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • Juniper Networks Junos OS

    fixed in 23.2R2-S7; From 23.4 · fixed in 23.4R2-S8; From 24.2 · fixed in 24.2R2-S4; From 24.4 · fixed in 24.4R2-S4

References 1

supportportal.juniper.net