CVE-2026-20122
MediumExploitedPublic exploitCisco Catalyst SD-WAN Manager Arbitrary File Overwrite Vulnerability
Published Feb 25, 2026 · Updated Apr 21, 2026
Key Facts
Patch immediately- CVE-2026-20122 is a medium-severity vulnerability (CVSS 5.4 v3.1) affecting Catalyst SD-WAN Manager (Cisco).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 5, 2026. Public exploit code is available.
- EPSS estimates a 25% probability of exploitation in the next 30 days.
- Fixed versions are available, including Catalyst SD-WAN Manager 20.9.8.2.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
25%
Higher than 97.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-20122 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Apr 20, 2026 | Apr 23, 2026 | Not reported |
| Industry KEV feed | Mar 5, 2026 | Apr 23, 2026 | Not reported |
| CIRCL KEV | Apr 20, 2026 | Apr 23, 2026 | Not reported |
| ENISA EUVD | Apr 20, 2026 | n/a | Not reported |
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.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Catalyst SD-WAN ManagerCisco | 20.12.6, >= 20.1.12 | 20.9.8.2 |
Patched Releases
Catalyst SD-WAN Manager
20.9.8.2
Timeline
Publicly disclosed
Feb 25, 2026
Added to Industry KEV feed
Mar 5, 2026
Added to CISA KEV
Apr 20, 2026
Added to CIRCL KEV
Apr 20, 2026
Added to ENISA EUVD
Apr 20, 2026
Last updated
Apr 21, 2026
Weakness Type
- CWE-648 Incorrect Use of Privileged APIs
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- othercisco-sa-sdwan-authbp-qwCX8D4v
FAQ
Common Questions.
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.
Affected: Catalyst SD-WAN Manager (Cisco) versions 20.12.6, >= 20.1.12. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 5, 2026.
Yes. It was added on Apr 20, 2026 with a federal remediation due date of Apr 23, 2026.
Public exploit code is available.
Fixed versions are available, including Catalyst SD-WAN Manager 20.9.8.2.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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