RoomosOperating system · Cisco
CVE-2026-20156
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAs 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-2026-20156 are related to improper restriction of operations within the bounds of a memory buffer that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-119.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceBuffer overflow vulnerability in Cisco RoomOS software (CWE-119) discovered through internal security review. Improper restriction of operations within memory buffer bounds allows potential remote code execution or denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
RoomosOperating system
< 11.32.6.0>= 26.0.1.2, < 26.5.2.2
Roomos CloudOperating system
< 11.39.1.1>= 26.0.1.2, < 26.7.1.7CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine RoomOS versionAccess the device administration interface or use the 'xCommand SystemUnit SoftwareVersion' command via the API/CLI to retrieve the currently installed RoomOS versionAffected if The installed version is lower than the version listed in Cisco's security advisory for this CVE or is an unpatched release
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Verify device network exposureCheck network configuration settings to determine if the RoomOS device has reachable management interfaces (HTTP/HTTPS, SSH, or SIP ports) from untrusted networksAffected if The device management interfaces are exposed to the internet or untrusted LAN segments without proper firewall controls
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Review system logs for anomaliesExamine RoomOS system logs (via admin interface or 'xPreference Logging' commands) for unexpected processes, authentication failures, or memory-related errors occurring around the time frame of the CVE disclosureAffected if Logs contain buffer overflow error messages, unexpected service restarts, or indicators of exploitation attempts
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Check for unauthorized configuration changesReview device configuration settings via 'xConfiguration' commands or the admin interface for any unexpected modifications to security settings, user accounts, or network parametersAffected if Configuration shows unauthorized changes or the device exhibits unexpected behavior such as spontaneous reboots or service degradation
A user is affected if their RoomOS version predates the patch release and the device is network-accessible to potential attackers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data11.32.6.011.39.1.126.5.2.2
Apply the Cisco RoomOS software hardening update/patch to all affected devices as specified in Cisco's release notes.
Fix this in Roomos
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20156 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20156 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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