{"id":"CVE-2026-33797","aliases":["EUVD-2026-21208","GHSA-3rpc-j6fw-646r"],"status":"published","title":"Junos OS and Junos OS Evolved: An attacker sending a specific genuine BGP packet causes a BGP reset","description":"An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n  *  25.2 versions before 25.2R2\n\n\nThis issue does not affect Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n  *  25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue does not affect Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected.","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:A/V:C/RE:M/U:Green","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00174,"percentile":0.0693,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2026-04-09T21:31:22Z","modified":"2026-10-26T22:10:00Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper","product":"junos_os_evolved"},{"vendor":"juniper networks","product":"junos os"},{"vendor":"juniper networks","product":"junos os evolved"}],"references":[{"url":"https://kb.juniper.net/JSA107850","tags":["vendor-advisory","Vendor Advisory"]},{"url":"https://supportportal.juniper.net/JSA107850","tags":["vendor-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33797"},{"url":"https://github.com/advisories/GHSA-3rpc-j6fw-646r"}],"sources":{"cve":[{"id":"CVE-2026-33797","title":"Junos OS and Junos OS Evolved: An attacker sending a specific genuine BGP packet causes a BGP reset","description":"An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n  *  25.2 versions before 25.2R2\n\n\nThis issue does not affect Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n  *  25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue does not affect Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected.","status":"published","published":"2026-04-09T21:31:22.902Z","modified":"2026-04-23T20:08:35.655Z","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:A/V:C/RE:M/U:Green","level":"high","assessor":"cna"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:20:08.009733Z"}],"euvd":[{"id":"EUVD-2026-21208","description":"An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n  *  25.2 versions before 25.2R2\n\n\nThis issue does not affect Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n  *  25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue does not affect Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected.","status":"published","published":"2026-04-09T21:31:22Z","modified":"2026-04-23T20:08:35Z","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:A/V:C/RE:M/U:Green","level":"high"}],"updated_at":"2026-11-02T19:24:18.636842Z"}],"ghsa":[{"id":"GHSA-3rpc-j6fw-646r","title":"An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved...","description":"An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n  *  25.2 versions before 25.2R2\n\n\nThis issue doesn't not affected Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n  *  25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue doesn't not affected Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected.","status":"published","published":"2026-04-10T00:30:29Z","modified":"2026-04-23T21:32:27Z","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:A/V:C/RE:M/U:Green","level":"high"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:07:37.11234Z"}],"nvd":[{"id":"CVE-2026-33797","description":"An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).\n\nAn attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:\n\n  *  25.2 versions before 25.2R2\n\n\nThis issue does not affect Junos OS versions before 25.2R1.\n\nThis issue affects Junos OS Evolved: \n  *  25.2-EVO versions before 25.2R2-EVO\n\n\nThis issue does not affect Junos OS Evolved versions before 25.2R1-EVO.\n\neBGP and iBGP are affected.\nIPv4 and IPv6 are affected.","status":"published","published":"2026-04-09T22:16:29.547Z","modified":"2026-10-26T22:10:00.163Z","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:A/V:C/RE:M/U:Green","level":"high","assessor":"secondary"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:12:13.902911Z"}]}}