CVE-2026-63462highCWE-674

CVE-2026-63462: high-severity vulnerability in unleash

Unleash: Unauthenticated single-request DoS via OpenAPI validation error formatter

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.5epss 0.7%
Unleash is an open-source feature management platform. Prior to 7.5.2, 7.6.5, and 8.0.2, the shared OpenAPI validation error path in src/lib/error/bad-data-error.ts passes a raw request value from lodash.get to JSON.stringify in genericErrorMessage and fromOpenApiValidationErrors without guarding stack exhaustion. An unauthenticated attacker can send a roughly 10 KB JSON value nested thousands of levels deep to POST /edge/validate, POST /edge/issue-token, or another OpenAPI-validated endpoint, causing RangeError: Maximum call stack size exceeded in openAPIValidationMiddleware and terminating the Node process because no uncaughtException handler recovers it. Replaying the request can sustain a complete service outage. This issue is fixed in versions 7.5.2, 7.6.5, and 8.0.2.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Unleash · unleash
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