Cyber Resilience

CVE-2026-20122

Cisco Catalyst Sd-Wan Manager ≤ 20.9.8.2

CISA KEVActive ExploitationEUVD Exploited
Published
25 February 2026
Modified
21 April 2026
Patch / advisory
CVSS Score v3.1 5.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.25 98th percentile
Risk Priority 75 floored blend · peak EPSS

Summary

CVE-2026-20122 is a medium-severity Incorrect Use of Privileged APIs (CWE-648) vulnerability in Cisco Catalyst Sd-Wan Manager. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Abuse Elevation Control Mechanism (T1548); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and AC-3 (Access Enforcement) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-20122 is a vulnerability in the API of Cisco Catalyst SD-WAN Manager that stems from improper file handling on the API interface. An authenticated, remote attacker with valid read-only credentials and API access could exploit this issue to overwrite arbitrary files on the local file system of the affected system.

To exploit the vulnerability, an attacker must possess valid read-only credentials granting API access to the Cisco Catalyst SD-WAN Manager. By uploading a malicious file via the API, the attacker can overwrite arbitrary files, potentially gaining vmanage user privileges. The CVSS v3.1 base score is 5.4 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N), associated with CWE-648.

Mitigation details are available in the Cisco Security Advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-authbp-qwCX8D4v. The vulnerability is also listed in the CISA Known Exploited Vulnerabilities Catalog at https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20122.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
KEV Date Added
See CISA KEV catalog

Related Threats

MITRE ATT&CK Enterprise Techniques

T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1548.001 Setuid and Setgid Privilege Escalation
An adversary may abuse configurations where an application has the setuid or setgid bits set in order to get code running in a different (and possibly more privileged) user’s context.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20126Same product: Cisco Catalyst Sd-Wan Manager
CVE-2026-20128Same product: Cisco Catalyst Sd-Wan Managerboth on KEV
CVE-2026-20262Same product: Cisco Catalyst Sd-Wan Managerboth on KEV
CVE-2026-20133Same product: Cisco Catalyst Sd-Wan Managerboth on KEV
CVE-2026-20129Same product: Cisco Catalyst Sd-Wan Manager
CVE-2026-20127Same product: Cisco Catalyst Sd-Wan Managerboth on KEV
CVE-2023-20252Same product: Cisco Catalyst Sd-Wan Manager
CVE-2023-20261Same product: Cisco Catalyst Sd-Wan Manager
CVE-2026-20210Same product: Cisco Catalyst Sd-Wan Manager
CVE-2024-20475Same product: Cisco Catalyst Sd-Wan Manager

Affected Assets

cisco
catalyst sd-wan manager
20.12.6 · ≤ 20.9.8.2 · 20.10 — 20.12.5.3 · 20.13 — 20.15.4.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V3.5.2
  • V6.4.6

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover incorrect calls to privileged APIs before deployment.

Enforces authorization checks around privileged operations so that an API requiring elevated rights cannot be reached or misused without proper rights.

Least-privilege assignment directly reduces both the availability of privileged APIs and the blast radius when they are invoked incorrectly.

Security engineering principles include correct use of privileged interfaces and safe invocation patterns that stop the weakness from being introduced.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly enforce correct usage of privileged APIs during development.

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.

finds

Security testing can detect incorrect privileged API calls but does not prevent them at design time.

degrades

Restricting privileged utility programs limits the exposure of privileged APIs to misuse.

degrades

Privileged access rights directly govern the correct use of privileged APIs and reduce misuse.

prevents

Secure development lifecycle includes API usage standards that can prevent incorrect privileged calls.

prevents

Application security requirements can specify correct invocation of privileged APIs.

prevents

Secure architecture principles guide proper privilege separation and API usage.

References