What is the CVSS score of CVE-2026-20153?

CVE-2026-20153 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.3%.

Which versions of Cisco RoomOS are affected by CVE-2026-20153?

Cisco RoomOS contains a remote denial-of-service vulnerability (CVE-2026-20153, CVSS 7.5) allowing unauthenticated attackers to disable video conferencing and collaboration devices across your…

How to fix or mitigate CVE-2026-20153?

Within 24 hours, inventory all Cisco RoomOS installations and restrict network access to trusted subnets where operationally feasible. Within 7 days, contact Cisco support for interim mitigation guidance and implement network-level rate limiting on affected devices; enable detailed logging to detect exploitation attempts. Within 30 days, evaluate firmware upgrade and replacement timelines once patches become available, and establish a monitored vulnerability-tracking process for RoomOS systems in your environment.

Cisco RoomOS CVE-2026-20153

EUVD-2026-44719 HIGH

Improper Input Validation (CWE-20)

2026-07-15 cisco

GHSA-qm4f-8gwc-gx49

Cisco Information Disclosure Cisco Roomos Software

7.5

CVSS 3.1 · Vendor: cisco

Severity by source

Vendor (cisco) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

vuln.today AI

7.5 HIGH

Network-reachable service, no auth or interaction needed (PR:N/UI:N/AC:L); improper input validation yields only device crash/reload, so A:H with C:N/I:N.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Jul 15, 2026 - 16:48 vuln.today

CVE Published

Jul 15, 2026 - 16:18 cve.org

HIGH 7.5

DescriptionCVE.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-2026-20153 are related to improper input validation that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-20.

AnalysisAI

Denial of service in Cisco RoomOS software allows remote, unauthenticated attackers to disrupt device availability through improperly validated input, resulting in a high availability impact (CVSS 7.5). The flaw was internally discovered during a Cisco engineering security review and shipped in a software hardening release bundling multiple CWE-20 input-validation issues. There is no public exploit identified at time of analysis and it is not listed in CISA KEV.

Technical ContextAI

Cisco RoomOS is the operating system powering Cisco/Webex collaboration room endpoints and video devices (CPE cpe:2.3:a:cisco:cisco_roomos_software). The root cause is classed under CWE-20 (Improper Input Validation) - the Pillar weakness where the software fails to correctly validate the syntax, type, or bounds of externally supplied input before processing it. In this case the CVSS vector (C:N/I:N/A:H) indicates the mishandled input path leads to a resource or process disruption (crash/reload) rather than data exposure or modification, consistent with a network-reachable service on the device parsing attacker-controlled data. Cisco groups this and other internally found issues under a single hardening advisory.

RemediationAI

Patch available per vendor advisory - upgrade Cisco RoomOS to the fixed software hardening release identified in Cisco Security Advisory cisco-sa-hardening-roomos-AqNMbEq (https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-roomos-AqNMbEq); no exact fixed version number is present in the provided data, so consult the advisory for your specific device model and release train. As RoomOS endpoints are typically cloud-managed, ensure automatic software updates are enabled so the hardening release deploys. Until patched, reduce exposure by keeping RoomOS devices off the public internet and on segmented management/media VLANs, restricting network reachability to the device's signaling and management services to trusted infrastructure only, and blocking untrusted inbound access at the network edge - the trade-off is that overly aggressive filtering of call-signaling ports could disrupt legitimate video calls, so scope ACLs to management interfaces where possible.