{"id":"CVE-2026-57023","aliases":["EUVD-2026-42711","GHSA-8p3c-wvj4-2gqc"],"status":"published","title":"Junos OS: MX with SPC3, SRX Series: A specifically malformed TCP packet causes a flowd crash","description":"An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS).\n\nWhen TCP proxy is engaged in a flow session, to support ALGs, Advanced Anti-Malware, ICAP or UTM, a TCP packet with specifically malformed TCP header will cause flow processing daemon (flowd) to crash and restart. This causes a complete service outage until the system has automatically recovered.\n\n\n\nThis issue affects Junos OS on MX with SPC3, and SRX Series: \n\n\n\n  *  23.4 versions before 23.4R2-S7, \n  *  24.2 versions before 24.2R2-S4, \n  *  24.4 versions before 24.4R2-S3,\n  *  25.2 versions before 25.2R2.\n\n\n\n\nThis issue does not affect releases before 23.4R1.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0046,"percentile":0.40351,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1284"],"published":"2026-07-09T21:06:34Z","modified":"2026-10-25T15:10:00Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper networks","product":"junos os"}],"references":[{"url":"https://supportportal.juniper.net/JSA110083","tags":["vendor-advisory","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57023"},{"url":"https://github.com/advisories/GHSA-8p3c-wvj4-2gqc"}],"sources":{"cve":[{"id":"CVE-2026-57023","title":"Junos OS: MX with SPC3, SRX Series: A specifically malformed TCP packet causes a flowd crash","description":"An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS).\n\nWhen TCP proxy is engaged in a flow session, to support ALGs, Advanced Anti-Malware, ICAP or UTM, a TCP packet with specifically malformed TCP header will cause flow processing daemon (flowd) to crash and restart. This causes a complete service outage until the system has automatically recovered.\n\n\n\nThis issue affects Junos OS on MX with SPC3, and SRX Series: \n\n\n\n  *  23.4 versions before 23.4R2-S7, \n  *  24.2 versions before 24.2R2-S4, \n  *  24.4 versions before 24.4R2-S3,\n  *  25.2 versions before 25.2R2.\n\n\n\n\nThis issue does not affect releases before 23.4R1.","status":"published","published":"2026-07-09T21:06:34.219Z","modified":"2026-07-10T15:28:45.274Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T13:43:44.898272Z"}],"euvd":[{"id":"EUVD-2026-42711","description":"An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS).\n\nWhen TCP proxy is engaged in a flow session, to support ALGs, Advanced Anti-Malware, ICAP or UTM, a TCP packet with specifically malformed TCP header will cause flow processing daemon (flowd) to crash and restart. This causes a complete service outage until the system has automatically recovered.\n\n\n\nThis issue affects Junos OS on MX with SPC3, and SRX Series: \n\n\n\n  *  23.4 versions before 23.4R2-S7, \n  *  24.2 versions before 24.2R2-S4, \n  *  24.4 versions before 24.4R2-S3,\n  *  25.2 versions before 25.2R2.\n\n\n\n\nThis issue does not affect releases before 23.4R1.","status":"published","published":"2026-07-09T21:06:34Z","modified":"2026-07-10T15:28:45Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M","level":"high"}],"updated_at":"2026-11-02T18:20:02.822464Z"}],"ghsa":[{"id":"GHSA-8p3c-wvj4-2gqc","title":"An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of...","description":"An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS).\n\nWhen TCP proxy is engaged in a flow session, to support ALGs, Advanced Anti-Malware, ICAP or UTM, a TCP packet with specifically malformed TCP header will cause flow processing daemon (flowd) to crash and restart. This causes a complete service outage until the system has automatically recovered.\n\n\n\nThis issue affects Junos OS on MX with SPC3, and SRX Series: \n\n\n\n  *  23.4 versions before 23.4R2-S7, \n  *  24.2 versions before 24.2R2-S4, \n  *  24.4 versions before 24.4R2-S3,\n  *  25.2 versions before 25.2R2.\n\n\n\n\nThis issue does not affect releases before 23.4R1.","status":"published","published":"2026-07-10T00:31:26Z","modified":"2026-07-10T00:31:33Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/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:X/RE:M/U:X","level":"high"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T15:09:22.722529Z"}],"nvd":[{"id":"CVE-2026-57023","description":"An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS).\n\nWhen TCP proxy is engaged in a flow session, to support ALGs, Advanced Anti-Malware, ICAP or UTM, a TCP packet with specifically malformed TCP header will cause flow processing daemon (flowd) to crash and restart. This causes a complete service outage until the system has automatically recovered.\n\n\n\nThis issue affects Junos OS on MX with SPC3, and SRX Series: \n\n\n\n  *  23.4 versions before 23.4R2-S7, \n  *  24.2 versions before 24.2R2-S4, \n  *  24.4 versions before 24.4R2-S3,\n  *  25.2 versions before 25.2R2.\n\n\n\n\nThis issue does not affect releases before 23.4R1.","status":"published","published":"2026-07-09T22:17:07.397Z","modified":"2026-10-25T15:10:00.147Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/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:X/RE:M/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-1284"],"updated_at":"2026-11-02T14:12:28.4135Z"}]}}