Vulnerability · Published Aug 13, 2026 · Assigned by GitHub_M
CVE-2026-73647Quasar Framework: Prototype pollution in Quasar extend() utility
Medium 5.6
In plain English
A medium-severity prototype pollution in quasar from quasarframework. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Quasar Framework is a framework for building high-performance Vue.js user interfaces. Prior to 2.22.0, the public extend() utility in ui/src/utils/extend/extend.js recursively copied attacker-controlled object keys during extend(true, target, source) deep merges without rejecting an own __proto__ property. The merge could descend into the prototype object and write attacker-controlled properties to Object.prototype in the same JavaScript process. Applications that passed user-controlled or partially user-controlled objects to extend() could experience logic bypass, unsafe default-option injection, denial of service, or other application-specific impact when polluted properties were later consumed. This issue is fixed in version 2.22.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | quasar | 2.22.0 | GHSA-3r53-75j5-3g7j |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| quasarframework | quasar | < 2.22.0 |
Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L