CVE-2026-20110
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 · uneditedA vulnerability in the CLI of Cisco IOS XE Software could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because incorrect privileges are associated with the start maintenance command. An attacker could exploit this vulnerability by accessing the management CLI of the affected device as a low-privileged user and using the start maintenance command. A successful exploit could allow the attacker to put the device in maintenance mode, which shuts down interfaces, resulting in a denial of service (DoS) condition. In case of exploitation, a device administrator can connect to the CLI and use the stop maintenance command to restore operations.
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 · high confidenceA privilege escalation vulnerability exists in Cisco IOS XE Software where the 'start maintenance' command is incorrectly associated with low-privileged user access. An authenticated low-privileged user can execute this command to place the device into maintenance mode, which shuts down all interfaces and causes a denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/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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Identify IOS XE versionRun 'show version' on the device and locate the IOS XE version string (typically in the format IOS XE X.X.X)Affected if The device runs any version of Cisco IOS XE Software and the 'start maintenance' command is accessible to non-privilege level 15 users
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Check privilege level for maintenance commandsRun 'show privilege' and examine the current user privilege level, then check if 'start maintenance' and 'stop maintenance' commands are available at the user's current privilege level by attempting to enter maintenance mode or reviewing the command privilege configuration with 'show running-config | include privilege'Affected if A user with privilege level below 15 can access the 'start maintenance' command (privilege level 0-14)
A user is affected if they are running Cisco IOS XE Software and low-privileged authenticated users (privilege level below 15) can execute the 'start maintenance' command to trigger maintenance mode.
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 dataRestrict the 'start maintenance' and 'stop maintenance' commands to administrator-level privilege (privilege level 15) using the Cisco IOS XE privilege command configuration to prevent low-privileged users from triggering maintenance mode.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20110 — 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-2026-20110 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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- Version or environment caveats, and links to real fixes
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