CVE-2025-57353 is a medium-severity (CVSS 5.3) CWE-1321 vulnerability in @messageformat/runtime. O3 Security confirms whether CVE-2025-57353 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
messageformat prototype pollution vulnerability
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@messageformat/runtimenpmDescription
The Runtime components of messageformat package for Node.js before 3.0.2 contain a prototype pollution vulnerability. Due to insufficient validation of nested message keys during the processing of message data, an attacker can manipulate the prototype chain of JavaScript objects by providing specially crafted input. This can result in the injection of arbitrary properties into the Object.prototype, potentially leading to denial of service conditions or unexpected application behavior. The vulnerability allows attackers to alter the prototype of base objects, impacting all subsequent object instances throughout the application's lifecycle.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @messageformat/runtime | ≥ 3.0.1&&< 3.0.2 | 3.0.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @messageformat/runtime. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @messageformat/runtime to 3.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-57353 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-57353 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-57353. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-57353 in your dependencies?
O3 detects CVE-2025-57353 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.