Description

Flags SDK is an open-source feature flags toolkit for Next.js and SvelteKit. Impacted versions include flags from 3.2.0 and prior and @vercel/flags from 3.1.1 and prior as certain circumstances allows a bad actor with detailed knowledge of the vulnerability to list all flags returned by the flags discovery endpoint (.well-known/vercel/flags). This vulnerability allows for information disclosure, where a bad actor could gain access to a list of all feature flags exposed through the flags discovery endpoint, including the flag names, flag descriptions, available options and their labels (e.g. true, false), and default flag values. This issue has been patched in [email protected], users of flags and @vercel/flags should also migrate to [email protected].

Classification

CVE ID: CVE-2025-46332

CVSS Base Severity: MEDIUM

CVSS Base Score: 6.5

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected Products

Vendor: vercel

Product: flags

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 9.04% (scored less or equal to compared to others)

EPSS Date: 2025-05-31 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: true

References

https://nvd.nist.gov/vuln/detail/CVE-2025-46332
https://github.com/vercel/flags/security/advisories/GHSA-892p-pqrr-hxqr
https://github.com/vercel/flags/blob/main/packages/flags/guides/upgrade-to-v4.md
https://vercel.com/changelog/information-disclosure-in-flags-sdk-cve-2025-46332

Timeline