{"cve":"CVE-2021-1588","nvd":{"published":"2021-08-25T20:15:11.537","modified":"2026-06-17T03:32:07.037","status":"Modified","description":"A vulnerability in the MPLS Operation, Administration, and Maintenance (OAM) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper input validation when an affected device is processing an MPLS echo-request or echo-reply packet. An attacker could exploit this vulnerability by sending malicious MPLS echo-request or echo-reply packets to an interface that is enabled for MPLS forwarding on the affected device. A successful exploit could allow the attacker to cause the MPLS OAM process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","score":8.6},"cwes":["CWE-20","CWE-125","CWE-126"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-mpls-oam-dos-sGO9x5GM","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-mpls-oam-dos-sGO9x5GM"],"products":["cisco:nx-os"],"source":"nvd","synced_at":"2026-10-19T21:21:57.125947417+00:00"},"epss":{"cve":"CVE-2021-1588","score":0.01316,"percentile":0.70782,"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."]}