Account takeover via unverified SSO email linking
Published Jul 23, 2026 · Updated Jul 23, 2026
Improper authentication in Logto 1.11.0 through 1.37.1 allows remote attackers to take over local accounts through SSO. When no issuer-and-identity match exists, the SSO linking path looks up a local user by the IdP-supplied email and links the identity without requiring email_verified. An attacker needs a permissive upstream IdP that permits registration with the victim's unverified email; the first federated login then grants access to the victim's existing account.
Summary
What happened
Improper authentication in Logto 1.11.0 through 1.37.1 allows remote attackers to take over local accounts through SSO. When no issuer-and-identity match exists, the SSO linking path looks up a local user by the IdP-supplied email and links the identity without requiring email_verified. An attacker needs a permissive upstream IdP that permits registration with the victim's unverified email; the first federated login then grants access to the victim's existing account.
The record
- CVE
- CVE-2026-15611
- Published
- Jul 23, 2026
- Updated
- Jul 23, 2026
- Vendor
- Logto
- Product
- Logto
- Classifications
- CWE-287, T1078
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 23, 2026CVE publishedPublication date reported by the CVE source.
- Jul 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.11.0 <=1.37.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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