CVE-2026-20797
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 stack based buffer overflow exists in an API route of XWEB Pro version 1.12.1 and prior, enabling unauthenticated attackers to cause stack corruption and a termination of the program.
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 confidenceA stack-based buffer overflow vulnerability exists in an API route of XWEB Pro versions 1.12.1 and prior, allowing unauthenticated remote attackers to corrupt stack memory, leading to program termination. The critical CVSS score of 9.8 indicates trivial network-exploitable attack vector with no authentication required.
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<= 1.12.1<= 1.12.1<= 1.12.1CVSS 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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Identify the XWEB Pro modelLocate the device model number through the web interface, physical label, or SNMP inventory. Confirm it is one of: Xweb 300d Pro, Xweb 500d Pro, or Xweb 500b Pro.Affected if The device model is any of these three Pro variants.
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Check the firmware versionAccess the device admin panel or use the firmware version check command (typically available via web UI under 'System Info' or 'About'). Compare the installed firmware version to 1.12.1.Affected if The firmware version is 1.12.1 or lower.
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Verify API accessibilityDetermine if the device web interface/API is reachable from the network. Check for open HTTP/HTTPS ports (typically 80/443) on the XWEB device.Affected if The API is exposed on the network without network segmentation.
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Identify vulnerable API endpointReview any available device documentation or proxy logs to identify which API route handles unauthenticated requests. The vulnerability exists in an unauthenticated API route.Affected if The specific vulnerable API route is accessible without authentication.
A user is affected if they are running Copeland XWEB Pro firmware version 1.12.1 or lower on any of the three affected models with the API exposed to the network.
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 dataApply vendor patches or upgrade to a patched version of XWEB Pro. If no patch is available, implement network-level filtering or a WAF to block malicious requests to the vulnerable API endpoint.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20797 — 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-2026-20797 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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