CVE-2026-20128
CVE-2026-20128 is a high-severity vulnerability in Cisco Catalyst Sd-wan Manager with a CVSS 3.x base score of 7.5. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-04-20). The underlying weakness is classified as CWE-257.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 5% (92nd percentile)
- Actively exploited: Yes — listed in CISA KEV (added 2026-04-20)
- EU (EUVD) id: EUVD-2026-8676
- EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2026-04-20)
- Weakness: CWE-257
- Affected product: Cisco Catalyst Sd-wan Manager
- Published:
- Last modified:
Description
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.
Frequently asked questions
- What is CVE-2026-20128?
- 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.
- How severe is CVE-2026-20128?
- CVE-2026-20128 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-20128 being actively exploited?
- Yes. CVE-2026-20128 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-04-20, which means active exploitation has been confirmed. It should be prioritised for remediation.
- What products are affected by CVE-2026-20128?
- CVE-2026-20128 primarily affects Cisco Catalyst Sd-wan Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-20128?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
- Does CVE-2026-20128 have an EU (EUVD) identifier?
- Yes. CVE-2026-20128 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8676. It is also flagged as exploited in the EUVD (since 2026-04-20).
- When was CVE-2026-20128 published?
- CVE-2026-20128 was published on 2026-02-25 and last updated on 2026-06-17.
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-authbp-qwCX8D4v
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20128
Affected products (2)
- cpe:2.3:a:cisco:catalyst_sd-wan_manager:*:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:catalyst_sd-wan_manager:20.12.6:*:*:*:*:*:*:*
More vulnerabilities in Cisco Catalyst Sd-wan Manager
- CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…
- CVE-2026-20127 — Critical (CVSS 10.0): A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco…
- CVE-2026-20129 — Critical (CVSS 9.8): A vulnerability in the API user authentication of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote…
- CVE-2023-20252 — Critical (CVSS 9.8): A vulnerability in the Security Assertion Markup Language (SAML) APIs of Cisco Catalyst SD-WAN Manager Software could…
- CVE-2021-1508 — Critical (CVSS 9.8): Multiple vulnerabilities in Cisco SD-WAN vManage Software could allow an unauthenticated, remote attacker to execute…
- CVE-2021-1506 — Critical (CVSS 9.8): Multiple vulnerabilities in Cisco SD-WAN vManage Software could allow an unauthenticated, remote attacker to execute…
All CVEs affecting Cisco Catalyst Sd-wan Manager →
Other CWE-257 vulnerabilities
- CVE-2025-8095 — Critical (CVSS 9.1): The OECH1 prefix encoding is intended to obfuscate values across the OpenEdge platform. It has been identified as…
- CVE-2025-8904 — High (CVSS 8.5): Amazon EMR Secret Agent creates a keytab file containing Kerberos credentials. This file is stored in the /tmp/…
- CVE-2025-34180 — High (CVSS 8.4): NetSupport Manager < 14.12.0001 relies on a shared Gateway Key for authentication between Manager/Control, Client,…
- CVE-2025-6996 — High (CVSS 8.4): Improper use of encryption in the agent of Ivanti Endpoint Manager before version 2024 SU3 and 2022 SU8 Security Update…
- CVE-2025-6995 — High (CVSS 8.4): Improper use of encryption in the agent of Ivanti Endpoint Manager before version 2024 SU3 and 2022 SU8 Security Update…
- CVE-2016-15058 — High (CVSS 8.1): Hirschmann HiLCOS Classic Platform switches Classic L2E, L2P, L3E, L3P versions prior to 09.0.06 and Classic L2B prior…