Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-30230 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Flintsh Flare. Its CVSS base score is 8.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-30230 is an authorization bypass vulnerability (CWE-639) in Flare, a Next.js-based, self-hostable file sharing platform that integrates with screenshot tools. In versions prior to 1.7.2, the thumbnail endpoint does not validate passwords for password-protected files, despite checking ownership or admin privileges for private files. This flaw allows unauthorized access to thumbnails without the password. The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) and was published on 2026-03-06T21:16:17.077.
Remote attackers require no privileges or user interaction to exploit this issue over the network. By directly accessing the thumbnail endpoint with the identifier of a password-protected file, an unauthenticated adversary can retrieve the thumbnail image, disclosing potentially sensitive visual content that was meant to be restricted by the password mechanism.
The vulnerability has been patched in Flare version 1.7.2. Additional mitigation details are available in the GitHub security advisory at https://github.com/FlintSH/Flare/security/advisories/GHSA-3x7v-x3r6-mjh7.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10076
Vulnerability Data
Flare is a Next.js-based, self-hostable file sharing platform that integrates with screenshot tools. Prior to version 1.7.2, the thumbnail endpoint does not validate the password for password‑protected files. It checks ownership/admin for private files but skips password verification, allowing thumbnail…
more
access without the password. This issue has been patched in version 1.7.2.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Enforcing approved authorizations on every access request structurally stops a user-controlled key from reaching another user's data.
Requiring explicit access-control decisions on each request blocks unauthorized key-driven access.
Least-privilege restrictions limit the scope of data reachable even if a key check is bypassed.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing authorization policy and least privilege directly blocks user-controlled key tampering that bypasses access checks.
Logical access controls prevent unauthorized data access that results from missing authorization checks on object references.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing authorization checks but does not prevent the weakness in production.
Information access restriction explicitly enforces that users may only retrieve data they are authorized to see, directly addressing user-controlled key bypass.
Access control policy directly requires enforcement of authorization rules that prevent unauthorized access via manipulated keys.
Managing access rights includes ensuring users can only access their own records and not bypass authorization by altering identifiers.
Privileged access rights control restricts what data each user may access, mitigating direct object reference attacks.
Secure development lifecycle includes authorization design but does not itself implement runtime access checks.