CVE-2026-20122
Cisco Catalyst SD-WAN Manager Incorrect Use of Privileged APIs Vulnerability
Cisco Catalyst SD-WAN Manger
A vulnerability in the API of Cisco Catalyst SD-WAN Manager could allow an authenticated, remote attacker to overwrite arbitrary files on the local file system. To exploit this vulnerability, the attacker must have valid read-only credentials with API access on the affected system. This vulnerability is due to improper file handling on the API interface of an affected system. An attacker could exploit this vulnerability by uploading a malicious file on the local file system. A successful exploit could allow the attacker to overwrite arbitrary files on the affected system and gain vmanage user privileges.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 20 April 2026. US federal agencies were required to remediate it by 23 April 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 25.8%, which is higher than 98% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Frequently asked questions
Is CVE-2026-20122 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2026-20122.
What does CVE-2026-20122 affect?
CVE-2026-20122 affects Cisco Catalyst SD-WAN Manger. A vulnerability in the API of Cisco Catalyst SD-WAN Manager could allow an authenticated, remote attacker to overwrite arbitrary files on the local file system. To exploit this vulnerability, the attacker must have valid read-only credentials with API access on the affected system. This vulnerability is due to improper file handling on the API interface of an affected system. An attacker could exploit this vulnerability by uploading a malicious file on the local file system. A successful exploit could allow the attacker to overwrite arbitrary files on the affected system and gain vmanage user privileges.
How severe is CVE-2026-20122?
CVE-2026-20122 is rated MEDIUM with a CVSS base score of 5.4. EPSS puts the probability of exploitation in the next 30 days at 25.8%, higher than 98% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 23 April 2026.
How should organisations respond to CVE-2026-20122?
Apply the vendor patch for Cisco Catalyst SD-WAN Manger as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.