CVE-2021-44726
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 · uneditedKNIME Server before 4.13.4 allows XSS via the old WebPortal login page.
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 confidenceCross-site scripting (XSS) vulnerability in KNIME Server's legacy WebPortal login page allows attackers to inject malicious scripts via unsanitized input fields, potentially stealing session cookies or performing actions on behalf of authenticated users.
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< 4.13.4CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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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Locate KNIME Server installation and versionCheck your system for KNIME Server installation directories. Common locations include /opt/knime/server or C:\Program Files\KNIME\Server. Inside the installation, look for a VERSION file or check the knime-server.ini configuration for version information.Affected if The installed version is found to be below 4.13.4
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Identify the WebPortal in useAccess the KNIME Server web interface. Determine whether the legacy WebPortal login page is being used versus newer web clients. The legacy WebPortal typically uses a different URL path or interface than modern KNIME Analytics Platform web clients.Affected if The legacy WebPortal login interface is accessible or configured on the server
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Verify XSS input vector existsInspect the KNIME Server login page HTML source. Look for the legacy WebPortal login form at the expected endpoint. Check if input fields (username, password) render user-supplied data without sanitization by viewing the page source after submitting test input.Affected if Input fields in the legacy WebPortal login page accept and reflect unsanitized content
You are affected if your KNIME Server version is below 4.13.4 and the legacy WebPortal login page is accessible or enabled.
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 · scoped4.13.4
Upgrade KNIME Server to version 4.13.4 or later which contains the patch for this XSS vulnerability in the old WebPortal login page.
KNIME Server 4.13.4
- 1. Back up your current KNIME Server configuration and data.
- 2. Download KNIME Server version 4.13.4 or later from the official KNIME download portal.
- 3. Stop the KNIME Server service.
- 4. Install the upgraded KNIME Server version following the standard upgrade procedure.
- 5. Verify the WebPortal login page is updated and test for XSS vulnerability resolution.
- 6. Restart the KNIME Server service.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-44726 — 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-2021-44726 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
- No spam, self-promotion, credentials, or personal data