Vulnerability · Published Jul 23, 2026 · Assigned by certcc
CVE-2026-15611Unverified email-based SSO account linking
Critical 9.1
In plain English
A critical-severity improper authentication in Logto from Logto. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.5%top 58.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Logto allows unverified email-based SSO account linking, enabling an attacker to register an identity at a permissive IdP using a victim’s email and gain unauthorized access to the victim’s account.
Affected products (as reported)
Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- https://github.com/logto-io/logto/blob/ea3ede35028dfd0bbb6d7b239623ce0e7f6cdff8/packages/core/src/libraries/verification-helpers/single-sign-on.ts#L274
- https://github.com/logto-io/logto/blob/ea3ede35028dfd0bbb6d7b239623ce0e7f6cdff8/packages/core/src/routes/experience/classes/verifications/enterprise-sso-verification.ts#L284-L297