CVEs / CVE-2026-20320
CVE-2026-20320: Cisco BroadWorks Improper Restriction of XML External Entity Reference Vulnerability
- Known exploited in the CISA KEV catalog since 10 Nov 2026
- high 7.5 CVSS 3.1 (from the CNA)
- EPSS 0.82% chance of exploitation in the next 30 days, higher than 57% of CVEs (11 Nov 2026)
- Last changed at its sources
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Summary
Cisco BroadWorks contains an improper restriction of XML external entity reference vulnerability that could allow an unauthenticated, remote attacker to read sensitive configuration information on an affected system.
Description
A vulnerability in the Open Client Interface (OCI) XML Parser of Cisco BroadWorks could allow an unauthenticated, remote attacker to read sensitive configuration information on an affected system. This vulnerability exists because XML entries are improperly parsed due to external entity resolution being allowed by default. An attacker could exploit this vulnerability by sending a crafted XML message to the Open Client Interface – Provisioning (OCI-P) service. A successful exploit could allow the attacker to view sensitive files from the filesystem with the privileges of the Cisco BroadWorks user.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Cisco Cisco BroadWorks | N/A | — |
Exploitation
| In CISA KEV since | 10 Nov 2026 |
|---|---|
| Due date for US federal agencies | 24 Nov 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-611 |
References
- CVE-2026-20320 on NVD
- CVE-2026-20320 in the CISA KEV catalog
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bworks-xxe-uwUd7CEt (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bworks-xxe-uwUd7CEt Vendor Advisory
- https://malbearlabs.com/posts/operation-snowball-inside-an-autonomous-ai-intrusion-campaign Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20320 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.