EUVD-2026-48300

| CVE-2026-15617 CRITICAL

Improper Handling of Case Sensitivity (CWE-178)

2026-07-23 cret@cert.org

GHSA-257m-4vpx-xg86

Authentication Bypass

9.1

CVSS 3.1 · Vendor: cert

Severity by source

Vendor (cert) PRIMARY

9.1 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Primary rating from Vendor (cert) · only source for this CVE.

CVSS VectorVendor: cert

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Analysis Generated

Jul 27, 2026 - 16:23 vuln.today

CVSS changed

Jul 27, 2026 - 16:22 NVD

9.1 (CRITICAL)

CVE Published

Jul 23, 2026 - 16:17 cve.org

UNKNOWN (no severity yet)

CVE Published

Jul 23, 2026 - 16:17 cve.org

CRITICAL 9.1

DescriptionCVE.org

Logto performs principal lookup without normalizing email and identifier strings, enabling principal collision and unauthorized account access via case- or Unicode-different identities.

AnalysisAI

Authentication bypass in Logto versions 1.10.1 through 1.37.1 allows remote attackers to gain unauthorized access to accounts by using email identifiers that differ only in case or Unicode representation, due to missing normalization during principal lookup. An attacker can register or authenticate with a case-variant of a target email and collide with the intended principal, leading to account takeover without user interaction. No active exploitation or public exploit code has been identified, and EPSS indicates low exploitation probability.