CVE-2026-20122: Cisco Catalyst SD-WAN Manager Incorrect Use of Privileged APIs Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Cisco Catalyst SD-WAN Manger. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-04-20, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-04-23; treat that as the outer limit, not the target.
• EPSS 25.5%, percentile 98: FIRST’s model estimates a 25.5% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.

What it is

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.

CISA’s summary

Cisco Catalyst SD-WAN Manager contains an incorrect use of privileged APIs vulnerability 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.

Weakness type: CWE-648.

Product: Cisco Catalyst SD-WAN Manger · Assigned by: cisco · Published: 2026-02-25

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-04-20; federal due date 2026-04-23. Known ransomware use: Unknown.
• CISA required action: Please adhere to CISA’s guidelines to assess exposure and mitigate risks associated with Cisco SD-WAN devices as outlines in CISA’s Emergency Directive 26-03 (URL listed below in Notes) and CISA’s “Hunt & Hardening Guidance for Cisco SD-WAN Devices (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.
• CISA SSVC assessment: exploitation active, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 25.48% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

• 2026-02-25 — CVE record published by cisco
• 2026-04-20 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-04-21 — CVE record last updated
• 2026-04-23 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Listed in CISA KEV notes (sec.cloudapps.cisco.com) sec.cloudapps.cisco.com

Vulnerability records

1. CVE.org record CVE-2026-20122 cve.org
2. NVD entry CVE-2026-20122 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov
3. Listed in CISA KEV notes (cisa.gov) cisa.gov

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