CVE-2026-20122
MEDIUMCVE-2026-20122 is a medium-severity (CVSS 5.4) CWE-648 vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-04-20) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
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,…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2026-04-20. Federal agencies were required to remediate by 2026-04-23.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2026-20122.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-20122 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 395,249 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Description
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.
Affected Products
catalyst sd-wan managerciscoDetection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2026-20122 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-20122 in your dependencies?
Find it across , including transitive dependencies.