What’s Vulnerable › Vulnerabilities

CVE-2026-73647: Quasar Framework: Prototype pollution in Quasar extend() utility

• Severity: medium (CVSS 5.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-13 · updated 2026-10-24
• Weakness: CWE-1321

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 products

• quasarframework quasar: before 2.22.0

References

• https://github.com/quasarframework/quasar/commit/d0a95d95ab3c29d13e1b8ba8c5e5025fd6ce35e7
• https://github.com/quasarframework/quasar/releases/tag/quasar-v2.22.0
• https://github.com/quasarframework/quasar/security/advisories/GHSA-3r53-75j5-3g7j
• https://github.com/quasarframework/quasar/security/advisories/GHSA-3r53-75j5-3g7j

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