{"id":"CVE-2026-57020","aliases":["EUVD-2026-42707","GHSA-vhf9-x75x-qgv5"],"status":"published","title":"Junos OS: QFX10000 Series: IPv6 multicast traffic received on non-IRB interfaces causes a multicast flood","description":"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).\n\nOn 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.\n\n\n\nThis issue affects Junos OS on QFX10000 Series:\n\n\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S8,\n  *  24.2 versions before 24.2R2-S4,\n  *  24.4 versions before 24.4R2-S4.\n\n\n\nThis issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.","severity":{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00269,"percentile":0.19249,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-754"],"published":"2026-07-09T21:05:07Z","modified":"2026-10-25T15:10:00Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper networks","product":"junos os"}],"references":[{"url":"https://supportportal.juniper.net/JSA110080","tags":["vendor-advisory","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57020"},{"url":"https://github.com/advisories/GHSA-vhf9-x75x-qgv5"}],"sources":{"cve":[{"id":"CVE-2026-57020","title":"Junos OS: QFX10000 Series: IPv6 multicast traffic received on non-IRB interfaces causes a multicast flood","description":"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).\n\nOn 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.\n\n\n\nThis issue affects Junos OS on QFX10000 Series:\n\n\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S8,\n  *  24.2 versions before 24.2R2-S4,\n  *  24.4 versions before 24.4R2-S4.\n\n\n\nThis issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.","status":"published","published":"2026-07-09T21:05:07.368Z","modified":"2026-07-10T13:29:08.357Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M","level":"high","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T13:43:44.898272Z"}],"euvd":[{"id":"EUVD-2026-42707","description":"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).\n\nOn 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.\n\n\n\nThis issue affects Junos OS on QFX10000 Series:\n\n\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S8,\n  *  24.2 versions before 24.2R2-S4,\n  *  24.4 versions before 24.4R2-S4.\n\n\n\nThis issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.","status":"published","published":"2026-07-09T21:05:07Z","modified":"2026-07-10T13:29:08Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M","level":"high"}],"updated_at":"2026-11-02T18:20:03.345658Z"}],"ghsa":[{"id":"GHSA-vhf9-x75x-qgv5","title":"An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding...","description":"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).\n\nOn 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.\n\n\n\nThis issue affects Junos OS on QFX10000 Series:\n\n\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S8,\n  *  24.2 versions before 24.2R2-S4,\n  *  24.4 versions before 24.4R2-S4.\n\n\n\nThis issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.","status":"published","published":"2026-07-10T00:31:26Z","modified":"2026-07-10T00:31:33Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:X","level":"high"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T15:09:22.722529Z"}],"nvd":[{"id":"CVE-2026-57020","description":"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).\n\nOn 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.\n\n\n\nThis issue affects Junos OS on QFX10000 Series:\n\n\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S8,\n  *  24.2 versions before 24.2R2-S4,\n  *  24.4 versions before 24.4R2-S4.\n\n\n\nThis issue does not affect Junos version after 24.4 as the QFX10000 Series devices are not supported on newer versions anymore.","status":"published","published":"2026-07-09T22:17:06.887Z","modified":"2026-10-25T15:10:00.147Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-754"],"updated_at":"2026-11-02T14:12:28.4135Z"}]}}