CVE-2026-54271
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-cli is the command line add-on for protobuf.js. Prior to 1.3.2 and 2.5.0, a previous fix for unsafe name handling in pbjs static / static-module code generation was incomplete. Affected versions of protobufjs-cli could still emit unsafe JavaScript references when generating static output from crafted JSON descriptor input. The common case of parsing schemas from .proto files is not affected. This is a bypass of CVE-2026-44295. An attacker who can provide or influence pre-parsed JSON descriptors passed to pbjs static code generation may be able to cause generated JavaScript output to contain attacker-controlled code. The injected code may execute if the generated file is later executed or imported and an affected generated API path is invoked. This vulnerability is fixed in 1.3.2 and 2.5.0.
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-cli versions prior to 1.3.2 and 2.5.0 contain an incomplete fix for unsafe name handling in pbjs static code generation. When untrusted or crafted JSON descriptors are passed to pbjs static, the generated JavaScript output can contain attacker-controlled code that executes if the generated file is later imported and an affected API path is invoked. This is a bypass of CVE-2026-44295. Parsing .proto files directly is not affected.
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< 1.3.2>= 2.0.0, < 2.5.0CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:L
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.
-
Check protobufjs-cli versionRun `npm list protobufjs-cli` or `npm list -g protobufjs-cli` if installed globally, or check package.json for the protobufjs-cli dependency versionAffected if The version is less than 1.3.2, or greater than or equal to 2.0.0 but less than 2.5.0
-
Identify if JSON descriptors are used with pbjs staticSearch project files for commands or scripts that invoke `pbjs static` with .json files (e.g., `pbjs -t json static input.json output.js` or similar patterns in build scripts, package.json scripts, or CI/CD pipelinesAffected if pbjs static is being used to process .json descriptor files rather than .proto files
-
Verify source of JSON descriptorsExamine the origin of any .json descriptor files passed to pbjs static. Check if they come from untrusted external sources, user input, or are generated from unknown .proto definitionsAffected if JSON descriptors are obtained from untrusted or unknown sources
-
Inspect generated JavaScript files for unsafe code patternsOpen the generated .js files from pbjs static and examine property names, method names, or object keys that could contain JavaScript code (e.g., look for unusual characters in property names, computed property access patterns, or code-like strings in unexpected places)Affected if Generated files contain unexpected code-like patterns in object property names or method definitions that could be attacker-controlled
You are affected if protobufjs-cli version is less than 1.3.2 or between 2.0.0 and 2.5.0 (exclusive), AND you use pbjs static to process JSON descriptors, especially from untrusted sources.
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 · scoped1.3.22.5.0
Upgrade protobufjs-cli to version 1.3.2 or 2.5.0. Audit and regenerate any static JavaScript files previously generated from untrusted JSON descriptor input, and avoid processing untrusted JSON descriptors with pbjs static code generation.
[email protected] (for versions <1.3.2) or [email protected] (for versions >=2.0.0 and <2.5.0)
- 1. Identify the currently installed protobufjs-cli version using 'npm list protobufjs-cli' or checking package.json
- 2. If version is < 1.3.2, upgrade to version 1.3.2: npm install [email protected]
- 3. If version is >= 2.0.0 and < 2.5.0, upgrade to version 2.5.0: npm install [email protected]
- 4. After upgrading, regenerate any static JavaScript files from JSON descriptors that may have been created using the vulnerable version
- 5. Re-deploy the newly generated files to replace potentially compromised outputs
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-54271 — 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-2026-54271 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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