CVE-2026-53520
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 · uneditedNezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 2.0.14 to before version 2.1.0, authenticated users can claim the dashboard Host through NAT and preempt all dashboard routing. This issue has been patched in version 2.1.0.
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 confidenceNezha Monitoring versions 2.0.14 through before 2.1.0 contain an improper access control vulnerability where authenticated users can claim the dashboard Host through NAT, allowing them to preempt all dashboard routing. This appears to be a flaw in the host claiming mechanism's handling of NAT'd connections and authorization checks.
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
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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 Nezha Monitoring versionCheck the installed Nezha Monitoring version through the admin UI or by inspecting the binary/container version (often visible in the dashboard footer, about page, or via CLI flags like -v)Affected if The installed version is 2.0.14 or higher but lower than 2.1.0
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Verify NAT exposure of dashboardDetermine if the Nezha dashboard is accessible from behind a NAT gateway or port-forwarded to the public internet. Inspect network configuration, firewall rules, and reverse proxy settings that route external traffic to the dashboard portAffected if The dashboard is reachable via NAT'd connections from untrusted networks
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Confirm authenticated access existsReview user accounts in Nezha Monitoring. Check if there are any non-admin or limited-privilege user accounts configured beyond the owner accountAffected if There are authenticated users other than the primary owner, or the dashboard permits user registration/login
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Inspect host claiming functionalityAccess the dashboard host management interface. Look for any host claiming or agent registration endpoints that accept connection metadata from NAT'd clients. Check if the API accepts client IP addresses from X-Forwarded-For headers without proper validationAffected if The host claiming endpoint accepts connections from NAT'd IPs and assigns ownership based on claim requests alone without additional authorization checks
You are affected if Nezha Monitoring version 2.0.14 through before 2.1.0 is running and the dashboard is accessible via NAT with authenticated users present.
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.
dbcve · scopedUpgrade to Nezha Monitoring version 2.1.0 or later. Since this vulnerability requires authenticated access, also review user permissions and consider implementing network-level controls for sensitive monitoring interfaces.
2.1.0
- Upgrade Nezha Monitoring to version 2.1.0 or later to resolve the improper access control vulnerability
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 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 $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-53520 — 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-2026-53520 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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- 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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