{"cve":"CVE-2023-36839","nvd":{"published":"2023-10-12T23:15:10.883","modified":"2026-06-17T06:07:11.623","status":"Modified","description":"An Improper Validation of Specified Quantity in Input vulnerability in the Layer-2 control protocols daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker who sends specific LLDP packets to cause a Denial of Service(DoS).\n\nThis issue occurs when specific LLDP packets are received and telemetry polling is being done on the device. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP. Also, if any services depend on LLDP state (like PoE or VoIP device recognition), then these will also be affected.\n\nThis issue affects:\n\nJuniper Networks Junos OS\n\n\n\n  *  All versions prior to 20.4R3-S8;\n  *  21.1 version 21.1R1 and later versions;\n  *  21.2 versions prior to 21.2R3-S5;\n  *  21.3 versions prior to 21.3R3-S4;\n  *  21.4 versions prior to 21.4R3-S3;\n  *  22.1 versions prior to 22.1R3-S2;\n  *  22.2 versions prior to 22.2R3;\n  *  22.3 versions prior to 22.3R2-S2;\n  *  22.4 versions prior to 22.4R2;\n\n\n\n\nJuniper Networks Junos OS Evolved\n\n\n\n  *  All versions prior to 20.4R3-S8-EVO;\n  *  21.1 version 21.1R1-EVO and later versions;\n  *  21.2 versions prior to 21.2R3-S5-EVO;\n  *  21.3 versions prior to 21.3R3-S4-EVO;\n  *  21.4 versions prior to 21.4R3-S3-EVO;\n  *  22.1 versions prior to 22.1R3-S2-EVO;\n  *  22.2 versions prior to 22.2R3-EVO;\n  *  22.3 versions prior to 22.3R2-S2-EVO;\n  *  22.4 versions prior to 22.4R1-S1-EVO;","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-1284"],"references":["https://supportportal.juniper.net/JSA73171","https://supportportal.juniper.net/JSA73171"],"products":["juniper:junos","juniper:junos_os_evolved"],"source":"nvd","synced_at":"2026-10-19T21:39:34.467980132+00:00"},"epss":{"cve":"CVE-2023-36839","score":0.00303,"percentile":0.23072,"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."]}