CVE-2026-27837
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 · uneditedDottie provides nested object access and manipulation in JavaScript. Versions 2.0.4 through 2.0.6 contain an incomplete fix for CVE-2023-26132. The prototype pollution guard introduced in commit `7d3aee1` only validates the first segment of a dot-separated path, allowing an attacker to bypass the protection by placing `__proto__` at any position other than the first. Both `dottie.set()` and `dottie.transform()` are affected. Version 2.0.7 contains an updated fix to address the residual 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 confidenceDottie versions 2.0.4-2.0.6 contain a bypass of an earlier prototype pollution fix. The original CVE-2023-26132 patch only validates the first segment of dot-separated paths, allowing attackers to inject `__proto__` or `constructor.prototype` at any position beyond the first segment to pollute Object prototypes. Both `dottie.set()` and `dottie.transform()` functions are vulnerable.
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>= 2.0.4, < 2.0.7CVSS 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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Check installed dottie versionRun `npm list dottie` or inspect the version field in node_modules/dottie/package.jsonAffected if version is 2.0.4, 2.0.5, or 2.0.6
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Identify usage of dottie.set()Search codebase for calls to dottie.set() or Dottie.set() and review whether user-controlled input flows into the first argumentAffected if user input can reach dottie.set() with dotted paths containing __proto__ at non-first positions (e.g., 'a.__proto__.b')
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Identify usage of dottie.transform()Search codebase for calls to dottie.transform() or Dottie.transform() and review whether user-controlled input flows into the object keysAffected if user input can reach dottie.transform() with object keys containing __proto__ at non-first positions in dotted paths
You are affected if dottie version is 2.0.4-2.0.6 AND your application passes user-supplied dotted paths to dottie.set() or dottie.transform() where __proto__ appears at any position other than the first segment.
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 · scoped2.0.7
Upgrade dottie to version 2.0.7 or later to apply the complete prototype pollution fix.
dottie version 2.0.7
- Update dottie package dependency to version 2.0.7 or later
- Run npm update dottie or npm install [email protected] to install the fixed version
- Verify the fix by running your test suite to ensure no regressions
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 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 $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-27837 — 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-2026-27837 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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- Version or environment caveats, and links to real fixes
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