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MessageformatApplication · Openjsf

CVE-2025-57349

HIGH · 7.5 CVSS v3.1 Published 2025-09-24
Fix available
A fix is available. Upgrade to 2.3.0 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
The messageformat package, an implementation of the Unicode MessageFormat 2 specification for JavaScript, is vulnerable to prototype pollution due to improper handling of message key paths in versions prior to 2.3.0. The flaw arises when processing nested message keys containing special characters (e.g., __proto__ ), which can lead to unintended modification of the JavaScript Object prototype. This vulnerability may allow a remote attacker to inject properties into the global object prototype via specially crafted message input, potentially causing denial of service or other undefined behaviors in applications using the affected component.

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 confidence

The messageformat package versions prior to 2.3.0 are vulnerable to prototype pollution due to improper sanitization of nested message keys containing special characters like __proto__. When the library processes these specially crafted keys, it allows modification of the JavaScript Object.prototype, potentially leading to denial of service or arbitrary code execution in applications using the affected component.

MitigationUpgrade messageformat to version 2.3.0 or later to receive the patch. Additionally, implement input validation to reject message keys containing special property names (__proto__, constructor, etc.) before passing them to the library.

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
MessageformatApplication
Affected:< 2.3.0

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
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Check installed messageformat version
    Run 'npm list messageformat' or inspect the version field in node_modules/messageformat/package.json
    Affected if The version listed is less than 2.3.0 or shows no version (package not found)
  2. Identify messageformat usage in your application
    Search your codebase for imports of 'messageformat' or require statements loading the messageformat module
    Affected if The application imports and uses messageformat to process messages
  3. Inspect message source files for special keys
    Review your message files (JSON, YAML, or .js files passed to messageformat compile) for keys containing __proto__, constructor, or other Object.prototype property names
    Affected if Message source files contain keys like '__proto__.foo' or 'constructor.foo' or similar nested keys with special property names
  4. Verify runtime message parsing
    If loading messages from external/untrusted sources at runtime, check if those sources can inject keys with __proto__ or constructor prefixes
    Affected if The application processes message keys from untrusted input without sanitizing special property names

You are affected if you use messageformat version below 2.3.0 AND your application processes message keys that include __proto__, constructor, or similar Object.prototype property names.

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 2.3.0 or later
Fixed in 2.3.0
Interim mitigation

Upgrade messageformat to version 2.3.0 or later to receive the patch. Additionally, implement input validation to reject message keys containing special property names (__proto__, constructor, etc.) before passing them to the library.

Recommended fix High confidence

2.3.0 or later

  1. Upgrade the messageformat package to version 2.3.0 or later by running: npm install messageformat@^2.3.0
  2. Verify the installed version matches or exceeds 2.3.0 using: npm list messageformat
  3. Test your application to ensure the upgrade does not break existing functionality

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

Fix this in Messageformat Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

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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-2025-57349 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
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  • Version or environment caveats, and links to real fixes
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