CVE-2026-44291
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 · uneditedprotobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs used plain objects with inherited prototypes for internal type lookup tables used by generated encode and decode functions. If Object.prototype had already been polluted, those lookup tables could resolve attacker-controlled inherited properties as valid protobuf type information. This could cause attacker-controlled strings to be emitted into generated JavaScript code. This vulnerability is fixed in 7.5.6 and 8.0.2.
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 confidenceprotobufjs versions prior to 7.5.6 and 8.0.2 use plain objects with inherited prototypes for internal type lookup tables in generated encode/decode functions. When Object.prototype is polluted, attackers can manipulate these lookup tables to inject arbitrary strings into generated JavaScript code, enabling code injection.
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< 7.5.6>= 8.0.0, < 8.0.2CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/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 protobufjs versionRun 'npm list protobufjs' in the project directory, or examine the package.json dependencies for the protobufjs version numberAffected if The installed version is less than 7.5.6, or greater than or equal to 8.0.0 but less than 8.0.2
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Identify protobufjs-generated code usageSearch the codebase for JavaScript files generated by protobufjs that contain the loadSync or fromJSON methods, or files with protobuf-type encode/decode functionsAffected if The application loads or executes JavaScript code generated by protobufjs for encoding or decoding protobuf messages
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Detect Object.prototype pollutionExecute 'Object.keys(Object.prototype)' or check for unexpected properties on Object.prototype such as non-standard __proto__, constructor modifications, or custom enumerable properties added to the prototypeAffected if Object.prototype contains unexpected or attacker-controlled properties beyond standard JavaScript built-in properties
You are affected if protobufjs version is in the vulnerable range AND your application uses protobufjs-generated encode/decode code AND Object.prototype is polluted in your runtime environment.
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 · scoped7.5.68.0.2
Upgrade protobufjs to version 7.5.6 or 8.0.2 and audit the application for existing prototype pollution vulnerabilities that could chain with this issue.
protobufjs 7.5.6 (for 7.x users) or protobufjs 8.0.2 (for 8.x users)
- Check the current protobufjs version in use by running `npm list protobufjs` or reviewing package.json
- If using protobufjs version 7.x, upgrade to version 7.5.6 or later by running `npm install protobufjs@^7.5.6`
- If using protobufjs version 8.x, upgrade to version 8.0.2 or later by running `npm install protobufjs@^8.0.2`
- Verify the upgrade was successful by running `npm list protobufjs` to confirm the installed version
- Test the application thoroughly in a non-production environment to ensure the upgrade does not break existing functionality
- Deploy the updated version to production after successful testing
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 h
- Testing8.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-44291 — 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-2026-44291 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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