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Vulnerability record · CVE-2021-1301 · published 20 January 2021

CVE-2021-1301: Cisco ios xe sd-wan memory buffer overflow vulnerability

Cisco · Ios Xe Sd Wan

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

9.8 CVSS 3.1 Critical EPSS 2.1% · top 19.0% CWE-119 · Memory buffer overflowCWE-20 · Improper input validation
9.8CVSS 3.1 base score, v2 7.5
2.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
5Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

5 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-bufovulns-B5NrSHbj Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-bufovulns-B5NrSHbj Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-1301), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.