dbcve.org
Live Share CanvasApplication · Microsoft

CVE-2026-45644

HIGH · 8.0 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 1.4.2 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable

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 · unedited
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Live Share Canvas SDK allows an authorized attacker to elevate privileges over a network.

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 confidence

Cross-site scripting (XSS) vulnerability in Microsoft Live Share Canvas SDK where improper input neutralization allows an authorized attacker to inject malicious scripts that can elevate privileges over a network connection.

MitigationImplement proper input validation and output encoding/sanitization on all user-supplied data rendered in the Canvas SDK; applyContent Security Policy headers to mitigate XSS execution; review and patch the specific injection points in the SDK.

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
Live Share CanvasApplication
Affected:< 1.4.2

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Live Share Canvas SDK installation
    Search your project dependencies (package.json, package-lock.json, yarn.lock, npm list) for '@microsoft/live-share-canvas' or 'live-share-canvas' package
    Affected if The package is present in dependencies and version is below 1.4.2
  2. Check installed SDK version
    Run 'npm list @microsoft/live-share-canvas' or inspect your lockfile to confirm the exact installed version number
    Affected if Installed version is less than 1.4.2 (e.g., 1.4.1, 1.4.0, 1.3.x, etc.)
  3. Determine if canvas feature is actively used
    Search your codebase for imports of Live Share Canvas SDK modules and usage of Canvas components (e.g., 'import { ... } from @microsoft/live-share-canvas')
    Affected if The Live Share Canvas SDK is imported and instantiated in your application code
  4. Identify user content rendering paths
    Inspect your canvas implementation code to see if user-generated content (shapes, text, sticky notes, drawings) is rendered without sanitization. Look for rendering functions that accept user input.
    Affected if User-supplied content is rendered on the canvas without evident sanitization or CSP enforcement
  5. Verify Content Security Policy headers
    Check your server response headers or HTML meta tags for 'Content-Security-Policy' header. Look for directives like 'script-src' that control inline script execution.
    Affected if CSP header is missing, weak (uses 'unsafe-inline'), or does not restrict script sources adequately

Your environment is affected if Live Share Canvas SDK version is below 1.4.2 AND your application renders user-generated content on the canvas without sanitization or strong CSP protection.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 1.4.2 or later
Fixed in 1.4.2
Interim mitigation

Implement proper input validation and output encoding/sanitization on all user-supplied data rendered in the Canvas SDK; applyContent Security Policy headers to mitigate XSS execution; review and patch the specific injection points in the SDK.

Recommended fix High confidence

1.4.2

  1. 1. Identify the project that depends on @microsoft/live-share-canvas or live-share-canvas package
  2. 2. Check the current installed version by examining package.json or running npm list @microsoft/live-share-canvas
  3. 3. Update the package.json dependency to version 1.4.2 or later: change "@microsoft/live-share-canvas": "^<current version>" to "@microsoft/live-share-canvas": "^1.4.2"
  4. 4. Run npm install or yarn install to update the dependency
  5. 5. Rebuild and test the application to verify the XSS vulnerability is remediated

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Live Share Canvas Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-45644 in production — separate from our analysis above.

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What this is

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.

What belongs here
  • 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