CVE-2026-20128 | Cisco Catalyst SD-WAN Manager Information Disclosure Vulnerability

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A vulnerability in the Data Collection Agent (DCA) feature of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to gain DCA user privileges on an affected system. This vulnerability is due to the presence of a credential file for the DCA user on an affected system. An attacker could exploit this vulnerability by sending a crafted HTTP request and reading the file that contains the DCA password from that affected system. A successful exploit could allow the attacker to access another affected system and gain DCA user privileges. Note: Cisco Catalyst SD-WAN Manager releases 20.18 and later are not affected by this vulnerability.

Published: 2026-02-25 Last update: 2026-04-21 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20128 is rated Active Exploitation (70/100): CVSS High severity, with low exploitation likelihood (EPSS 0.09%). CISA KEV confirms active exploitation (added 2026-04-20) affecting Cisco / Catalyst SD-WAN Manager. a weakness (CWE-257) Unauthenticated remote administrative access may be possible. Assess exposure and apply mitigations immediately; prioritize emergency patching.

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

CISA Known Exploited Vulnerabilities Catalog for CVE-2026-20128

KEV catalog lead: This CVE appears in the CISA Known Exploited Vulnerabilities catalog (in-the-wild exploitation signal). Full KEV detail: CVE-2026-20128 on KEV · Exploit-DB search ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-20128

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 2026-05-15 0.04% 0.09% +0.05%
2 2026-04-25 0.06% 0.04% -0.02%
3 2026-04-21 — 0.06% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20128

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.8 6.0 [email protected]

Weakness enumeration for CVE-2026-20128

GitHub Security Advisory for CVE-2026-20128

GHSA-mp6j-7g85-8pg2 · Severity: high — A vulnerability in the Data Collection Agent (DCA) feature of Cisco Catalyst SD-WAN Manager could...

Affected software / configurations for CVE-2026-20128

Vendor Product Version Raw CPE
cisco catalyst_sd-wan_manager < 20.9.8.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.10, < 20.12.5.3 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.13, < 20.15.4.2 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager >= 20.16, < 20.18 cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
cisco catalyst_sd-wan_manager 20.12.6 cpe:2.3:a:cisco:catalyst_sd-wan_manager:20.12.6:*:*:*:*:*:*:*

References for CVE-2026-20128

cvelogic Threat Intelligence