{"cve":"CVE-2023-44186","nvd":{"published":"2023-10-11T21:15:09.890","modified":"2026-06-17T06:27:04.643","status":"Modified","description":"An Improper Handling of Exceptional Conditions vulnerability in AS PATH processing of Juniper Networks Junos OS and Junos OS Evolved allows an attacker to send a BGP update message with an AS PATH containing a large number of 4-byte ASes, leading to a Denial of Service (DoS). Continued receipt and processing of these BGP updates will create a sustained Denial of Service (DoS) condition.\n\nThis issue is hit when the router has Non-Stop Routing (NSR) enabled, has a non-4-byte-AS capable BGP neighbor, receives a BGP update message with a prefix that includes a long AS PATH containing large number of 4-byte ASes, and has to advertise the prefix towards the non-4-byte-AS capable BGP neighbor.\n\nNote: NSR is not supported on the SRX Series and is therefore not affected by this vulnerability.\nThis issue affects:\n\nJuniper Networks Junos OS:\n\n\n\n  *  All versions prior to 20.4R3-S8;\n  *  21.1 versions 21.1R1 and later;\n  *  21.2 versions prior to 21.2R3-S6;\n  *  21.3 versions prior to 21.3R3-S5;\n  *  21.4 versions prior to 21.4R3-S5;\n  *  22.1 versions prior to 22.1R3-S4;\n  *  22.2 versions prior to 22.2R3-S2;\n  *  22.3 versions prior to 22.3R2-S2, 22.3R3-S1;\n  *  22.4 versions prior to 22.4R2-S1, 22.4R3.\n\n\n\n\nJuniper Networks Junos OS Evolved\n\n\n\n  *  All versions prior to 20.4R3-S8-EVO;\n  *  21.1 versions 21.1R1-EVO and later;\n  *  21.2 versions prior to 21.2R3-S6-EVO;\n  *  21.3 versions prior to 21.3R3-S5-EVO;\n  *  21.4 versions prior to 21.4R3-S5-EVO;\n  *  22.1 versions prior to 22.1R3-S4-EVO;\n  *  22.2 versions prior to 22.2R3-S2-EVO;\n  *  22.3 versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO;\n  *  22.4 versions prior to 22.4R2-S1-EVO, 22.4R3-EVO.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-755"],"references":["https://supportportal.juniper.net/JSA73150","https://supportportal.juniper.net/JSA73150"],"products":["juniper:junos","juniper:junos_os_evolved"],"source":"nvd","synced_at":"2026-10-19T21:39:34.467980132+00:00"},"epss":{"cve":"CVE-2023-44186","score":0.00643,"percentile":0.50862,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}