CVE-2019-16769
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 · uneditedThe serialize-javascript npm package before version 2.1.1 is vulnerable to Cross-site Scripting (XSS). It does not properly mitigate against unsafe characters in serialized regular expressions. This vulnerability is not affected on Node.js environment since Node.js's implementation of RegExp.prototype.toString() backslash-escapes all forward slashes in regular expressions. If serialized data of regular expression objects are used in an environment other than Node.js, it is affected by this vulnerability.
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 confidenceThe serialize-javascript npm package before version 2.1.1 is vulnerable to Cross-site Scripting (XSS) due to improper escaping of unsafe characters in serialized regular expressions. This only affects non-Node.js environments since Node.js's RegExp.prototype.toString() automatically backslash-escapes forward slashes, providing protection that browsers lack.
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< 2.1.1CVSS 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
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/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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Find the installed version of serialize-javascriptCheck your package.json, package-lock.json, or run `npm list serialize-javascript` in your project directoryAffected if The version listed is less than 2.1.1 (for example, 2.1.0, 2.0.0, 1.x.x, etc.)
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Confirm browser-side usageIdentify whether serialize-javascript is included in client-side code, such as in HTML script tags, webpack/browserify bundles served to browsers, or any frontend JavaScript that loads this packageAffected if The package is bundled or loaded for browser execution (non-Node.js runtime)
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Identify RegExp serialization callsSearch your codebase for patterns like `serialize(regex)`, `serializeJavascript(regex)`, or any call to serialize-javascript that passes RegExp objects as inputAffected if Your code calls serialize-javascript with RegExp objects or objects containing RegExp values
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Verify unsafe output sinkCheck if serialized regex output is written to the DOM via innerHTML, document.write, or similar browser APIs without additional escapingAffected if The serialized output reaches the browser DOM without server-side re-escaping or sanitization
You are affected if serialize-javascript version is below 2.1.1, it runs in a browser environment, and RegExp objects are serialized to output that reaches the DOM.
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 data2.1.1
Upgrade serialize-javascript to version 2.1.1 or later to receive the patch that properly escapes unsafe characters in serialized regular expressions.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-16769 — 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-2019-16769 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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