CVE-2026-20262 | Cisco Catalyst SD-WAN Manager Arbitrary File Write Vulnerability

Exp

A vulnerability in the web UI of Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an authenticated, remote attacker to create a file or overwrite any file on the filesystem of an affected system. This vulnerability exists because the affected software does not properly validate user-supplied input during a file upload process. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected API endpoint of the affected system. A successful exploit could allow the attacker to create or overwrite any file on the underlying operating system. This file could later be used to elevate to root. To exploit this vulnerability, the attacker must have valid credentials with at least a lower-privileged, single-task user account.

Published: 2026-06-15 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20262 is rated Critical Active Threat (88.8/100): CVSS Medium severity, with high exploitation likelihood (EPSS 7.68%, 94th percentile). CISA KEV confirms active exploitation (added 2026-06-15) affecting Cisco / Catalyst SD-WAN Manager. a weakness (CWE-22) Unauthenticated remote administrative access may be possible. EPSS rose +6.31% over the last day, indicating growing attacker interest. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2026-20262

Name: Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability · CISA KEV detail

Exploit added: 2026-06-15

Action due: 2026-06-29

Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Exploit prediction scoring system (EPSS) score for CVE-2026-20262

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-25 1.37% 7.68% +6.31%
2 2026-06-23 1.15% 1.37% +0.23%
3 2026-06-17 — 1.15% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20262

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-20262

GitHub Security Advisory for CVE-2026-20262

GHSA-p45r-gcc9-fr7f · Severity: medium — A vulnerability in the web UI of Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could...

Affected software / configurations for CVE-2026-20262

Vendor Product Version Raw CPE
cisco catalyst_sd-wan_manager < 20.9.9.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.10, < 20.12.7.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.13, < 20.15.4.5 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.15.5, < 20.15.5.3 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.16, < 20.18.3.1 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 26.1, < 26.1.1.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*

References for CVE-2026-20262

cvelogic Threat Intelligence