{"cve":"CVE-2023-36841","nvd":{"published":"2023-10-12T23:15:10.967","modified":"2026-06-17T06:07:12.020","status":"Modified","description":"An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows a unauthenticated network-based attacker to cause an infinite loop, resulting in a Denial of Service (DoS).\n\nAn attacker who sends malformed TCP traffic via an interface configured with PPPoE, causes an infinite loop on the respective PFE. This results in consuming all resources and a manual restart is needed to recover.\n\nThis issue affects interfaces with PPPoE configured and tcp-mss enabled.\n\nThis issue affects Juniper Networks Junos OS\n\n\n\n  *  All versions prior to 20.4R3-S7;\n  *  21.1 version 21.1R1 and later versions;\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-S3;\n  *  22.1 versions prior to 22.1R3-S4;\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;","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-400"],"references":["https://supportportal.juniper.net/JSA73172","https://supportportal.juniper.net/JSA73172"],"products":["juniper:junos"],"source":"nvd","synced_at":"2026-10-19T21:39:34.467980132+00:00"},"epss":{"cve":"CVE-2023-36841","score":0.00616,"percentile":0.49535,"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."]}