Vulnerability · Published Jul 15, 2026 · Assigned by GitHub_M

CVE-2026-53514Better Auth: Unauthorized invitation acceptance via unverified email match in organization plugin

High 7.7

In plain English

A high-severity improper authentication in better-auth from better-auth. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.7High

Exploit odds (30 days)0.2%top 90.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, and in 1.6.14 and later when invitation IDs can be obtained outside the invited mailbox and requireEmailVerificationOnInvitation: true is not enabled, the organization plugin's acceptInvitation, rejectInvitation, getInvitation, and listUserInvitations recipient endpoints use session.user.email and an invitation ID without sufficient verified-email ownership proof, allowing a user with an unverified session for the invited email address to accept an organization invitation after obtaining the invitation ID. This issue is fixed for the original default behavior in version 1.6.11, while 1.6.14 restored compatibility for built-in opaque invitation IDs and leaves affected configurations requiring secure options.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	better-auth	1.6.11	GHSA-fmh4-wcc4-5jm3

Affected products (as reported)

Vendor	Product	Versions
better-auth	better-auth	< 1.6.11

Weakness: CWE-287, CWE-345, CWE-441, CWE-862 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

References

https://github.com/better-auth/better-auth/security/advisories/GHSA-fmh4-wcc4-5jm3 x_refsource_CONFIRM
https://github.com/better-auth/better-auth/pull/9577 x_refsource_MISC
https://github.com/better-auth/better-auth/commit/23094a628f007f801be6d26e5b15dc5fc6fc4eb8 x_refsource_MISC
https://github.com/better-auth/better-auth/releases/tag/v1.6.11 x_refsource_MISC