CVE-2026-20245
Cisco Catalyst Sd-Wan Manager ≤ 20.9.9.1
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-20245 is a high-severity Improper Encoding or Escaping of Output (CWE-116) vulnerability in Cisco Catalyst Sd-Wan Manager. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A vulnerability in the CLI of Cisco Catalyst SD-WAN Controller (formerly vSmart), Cisco Catalyst SD-WAN Manager (formerly vManage), and Cisco Catalyst SD-WAN Validator (formerly vBond) allows an authenticated local attacker to execute arbitrary commands as root. The issue stems from insufficient validation of user-supplied input, enabling command injection when a crafted file is uploaded to the affected system. It carries a CVSS 3.1 score of 7.8 and is tracked under CWE-116.
An attacker must possess netadmin privileges, which can be obtained through valid credentials or by chaining with other vulnerabilities, to exploit the flaw and achieve root-level command execution. Cisco has observed limited instances of successful exploitation that resulted in configuration changes being pushed to edge devices, though the vendor states it is not aware of exploitation via other methods.
The Cisco Security Advisory published on May 14, 2026, recommends upgrading to the fixed software releases and verifying the configuration of edge devices. The vulnerability is also referenced in the CISA Known Exploited Vulnerabilities catalog.
The current EPSS score stands at 0.0033.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-34341
Vulnerability Data
A vulnerability in the CLI of Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an authenticated, local attacker to execute arbitrary commands as root…
more
by supplying a crafted file to the affected system. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by uploading a crafted file to the affected system. A successful exploit could allow the attacker to perform command injection attacks on an affected system and elevate their privileges as the root user. To exploit this vulnerability, the attacker must have netadmin privileges on the affected system. This would require valid credentials or exploitation of or . Cisco is not aware of successful exploitation by other methods. Cisco has observed limited cases where the exploitation of this bug resulted in a configuration change pushed to edge devices. Cisco recommends that customers upgrade to the fixed software that is documented in the that was published on May 14, 2026, and verify the configuration of the edge devices.
- CWE(s)
- KEV Date Added
- 09 June 2026
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.1.2V1.2.1V1.2.3
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Validating that output matches expected content directly mitigates failures to properly encode or escape data for its destination context.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require proper output encoding to prevent injection and message malformation.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding standards explicitly require correct output encoding and escaping to preserve message structure.
Security testing can detect missing or incorrect encoding but does not itself implement the control.
Secure development life cycle mandates output encoding/escaping practices that directly prevent improper encoding.
Application security requirements include explicit rules for safe output handling and encoding.
Secure architecture principles reduce the likelihood of missing encoding but do not prescribe the actual technique.