CVE-2026-54714

MEDIUM 6.1

Logto: XSS via unescaped RelayState in SAML auto-submit form

CVSS Score

6.1

EPSS Score

0.3%

EPSS Percentile

17th

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, @logto/core reflected the SAML RelayState, SAMLResponse, and actionUrl into a Logto-origin auto-submit HTML form in packages/core/src/saml-application/SamlApplication/utils.ts without HTML-attribute escaping. A SAML application flow with a crafted RelayState from GET or POST /api/saml/:id/authn could inject script that runs on the Logto tenant origin after the user completes login. This issue is fixed in version 1.41.0.

CWE	CWE-79
Vendor	logto-io
Product	logto
Published	Jul 10, 2026
Last Updated	Jul 13, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

logto-io / logto

< 1.41.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/logto-io/logto/security/advisories/GHSA-cpm5-w86q-w85f github.com: https://github.com/logto-io/logto/pull/9008 github.com: https://github.com/logto-io/logto/commit/209fa0a5cbe8522f9cf31873239dc6424099bb5e github.com: https://github.com/logto-io/logto/releases/tag/v1.41.0