Full Report
Cisco security advisory (AV26-602)
Analysis Summary
# Vulnerability: Cisco Catalyst SD-WAN Manager Arbitrary File Write
## CVE Details
- **CVE ID:** CVE-2026-20262
- **CVSS Score:** 9.8 (Critical) - *Estimated based on vulnerability type and CISA KEV inclusion*
- **CWE:** CWE-22 (Improper Limitation of a Pathname to a Restricted Directory / Arbitrary File Write)
## Affected Systems
- **Products:** Cisco Catalyst SD-WAN Manager (formerly vManage)
- **Versions:** Multiple versions are affected (Specific version ranges typically include 20.6, 20.9, 20.12, and 20.13)
- **Configurations:** All deployment types (On-premise and Cloud-based)
## Vulnerability Description
A vulnerability in the web-based management interface of Cisco Catalyst SD-WAN Manager allows an unauthenticated, remote attacker to perform arbitrary file writes on the underlying operating system. The flaw exists due to insufficient validation of user-supplied input. An attacker could exploit this by sending crafted requests to the affected system, allowing them to overwrite sensitive files or upload malicious scripts.
## Exploitation
- **Status:** **Exploited in the wild.** Added to CISA’s Known Exploited Vulnerabilities (KEV) Catalog on June 15, 2026.
- **Complexity:** Low
- **Attack Vector:** Network (Remote)
## Impact
- **Confidentiality:** High (Potential for full system compromise and data exfiltration)
- **Integrity:** High (Attacker can modify or overwrite critical system files)
- **Availability:** High (Attacker can crash services or render the manager inoperable)
## Remediation
### Patches
Cisco has released/is releasing software updates to address this vulnerability. Recommended fixed releases generally include:
- Catalyst SD-WAN Manager versions **20.12.x** and later
- Catalyst SD-WAN Manager versions **20.13.x** and later
- Users on legacy branches (20.6/20.9) should migrate to the latest patched maintenance release.
### Workarounds
There are no documented workarounds for this vulnerability. Security posture should be maintained by:
- Restricting access to the SD-WAN Manager interface via ACLs or VPNs.
- Ensuring only trusted internal networks can reach the management IP.
## Detection
- **Indicators of Compromise:** Monitor for unusual file modifications in web server directories, unauthorized administrative account creation, or unexpected outbound traffic from the SD-WAN Manager.
- **Detection methods and tools:**
- Review Cisco web UI access logs for suspicious POST requests.
- Use CISA’s KEV catalog to cross-reference with internal vulnerability scans.
## References
- Cisco Security Advisory: hxxps://sec[.]cloudapps[.]cisco[.]com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-arbfw-c2rZvQ
- CISA KEV Catalog: hxxps://www[.]cisa[.]gov/known-exploited-vulnerabilities-catalog
- Canadian Centre for Cyber Security (AV26-602): hxxps://www[.]cyber[.]gc[.]ca/en/alerts-advisories/cisco-security-advisory-av26-602