Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Network-reachable service exploitable without auth or interaction at low complexity, causing availability loss only, so C:N/I:N/A:H with PR:N/UI:N matches the disclosed DoS impact.
Primary rating from Vendor (cisco).
CVSS VectorVendor: cisco
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
2DescriptionCVE.org
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco RoomOS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.
The vulnerabilities tracked by CVE-2026-20187 are related to improper handling of exceptional conditions that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-703.
AnalysisAI
Denial of service in Cisco RoomOS software allows remote unauthenticated attackers to exhaust availability of affected collaboration endpoints and room-based video devices through improper handling of exceptional conditions (CWE-703). The issue was internally discovered by Cisco's RoomOS engineering team as part of a hardening release bundling multiple flaws under this identifier, carries a CVSS 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), and has no public exploit identified at time of analysis. Note that the CVSS vector reflects availability-only impact even though a source tag labels it 'Information Disclosure,' a discrepancy defenders should verify against the Cisco advisory.
Technical ContextAI
Cisco RoomOS is the software platform running on Cisco's Room, Board, and Desk collaboration endpoints (Webex-registered and on-premises video conferencing hardware). The root cause is classified under CWE-703 (Improper Handling of Exceptional Conditions), a pillar-level weakness class describing failures to correctly detect, propagate, or recover from error states, unexpected inputs, or resource-limit conditions. In network-facing services, this class typically manifests as unhandled exceptions or malformed-input parsing paths that crash or hang a process, producing the availability impact reflected in the CVSS vector. The single affected CPE is cpe:2.3:a:cisco:cisco_roomos_software (all versions prior to the hardening release), and CVE-2026-20187 is described by Cisco as an umbrella tracking multiple internally discovered vulnerabilities addressed together.
RemediationAI
Apply the Cisco RoomOS software hardening release that addresses CVE-2026-20187; because RoomOS devices are typically cloud-managed (Webex Control Hub) or receive automatic/scheduled software updates, ensure endpoints are on the latest RoomOS train and that automatic upgrades are enabled so the fixed build is deployed. The input does not include an exact fixed version number, so consult the Cisco advisory (https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-roomos-AqNMbEq) for the precise patched release and confirm your fleet's build against it. As a compensating control until patched, restrict network reachability to the endpoints' management and signaling interfaces - place RoomOS devices on a segmented VLAN, limit inbound access to trusted Webex/on-prem call-control infrastructure, and block untrusted network paths to the devices; the trade-off is that overly aggressive filtering can break call setup, provisioning, or cloud registration, so validate against required Webex service endpoints before enforcing.
More in Cisco Roomos Software
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Missing-encryption weaknesses in Cisco RoomOS software (the OS for Cisco Webex/Room collaboration endpoints) were fixed
Privilege escalation via improper access control in Cisco RoomOS software allows an authenticated attacker with low-leve
Remote denial of service in Cisco RoomOS software allows unauthenticated attackers to exhaust or corrupt a resource over
Denial of service in Cisco RoomOS software allows remote, unauthenticated attackers to disrupt device availability throu
Credential exposure in Cisco RoomOS allows an authenticated low-privilege local user to capture user login credentials b
Root-level code execution in Cisco RoomOS via the USB driver allows an unauthenticated attacker with physical access to
Same technique Information Disclosure
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-44722
GHSA-xmhm-hhwr-f9fp