CVE-2026-11420
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 · uneditedTwo path traversal vulnerabilities in the Network Installation Service (NIS) of Altium Enterprise Server allow an unauthenticated network attacker to write arbitrary files to any writable location on the server filesystem and to read package archive files from the server. No authentication, session, or credentials are required. Because content-controlled files can be written to web-accessible directories, or used to overwrite application binaries or configuration files, exploitation can be escalated to remote code execution in the context of the service account, and can disclose deployment package contents. Altium 365 cloud deployments are not affected, as the Network Installation Service is not part of the cloud offering.
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 confidenceAltium Enterprise Server's Network Installation Service contains two path traversal vulnerabilities that allow an unauthenticated remote attacker to write arbitrary files to any writable location on the server filesystem and to read package archive files. Since files can be written to web-accessible directories or used to overwrite application binaries, this can be escalated to achieve remote code execution in the context of the service account.
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< 8.1.1CVSS 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.
-
Identify Altium Enterprise Server installationLocate the Altium Enterprise Server installation directory and identify the installed version by checking version files, about pages, or the installer database if availableAffected if Server is installed with a version below 8.1.1
-
Verify Network Installation Service statusCheck if the Network Installation Service (NIS) component is enabled and running on the Altium serverAffected if NIS is enabled and accessible on the network
-
Inspect NIS endpoint accessibilityDetermine whether NIS HTTP/HTTPS endpoints are exposed to the network without proper authentication controlsAffected if NIS endpoints are reachable from untrusted networks
The environment is affected if Altium On Prem Enterprise Server is running with version < 8.1.1 and the Network Installation Service is enabled and accessible.
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 · scoped8.1.1
Apply vendor patches when released and implement network-level access controls to restrict the NIS service to trusted networks until patching is complete.
8.1.1
- Back up the existing Altium Enterprise Server installation, including all databases, configuration files, and deployment packages
- Download Altium Enterprise Server version 8.1.1 or later from the official Altium download portal (www.altium.com)
- Review Altium's upgrade documentation for version 8.1.1 to ensure all prerequisites are met
- Execute the upgrade procedure according to Altium's official installation/upgrade guide for Enterprise Server
- Verify that the Network Installation Service (NIS) is properly running after upgrade
- Confirm the path traversal vulnerabilities are resolved by testing that file write operations are restricted to authorized directories
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,296.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-11420 — 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-2026-11420 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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
- No spam, self-promotion, credentials, or personal data