CVE-2026-54714: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in logto-io logto
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.
AI Analysis
Technical Summary
Logto versions before 1.41.0 contain a reflected cross-site scripting vulnerability due to improper neutralization of input during web page generation. Specifically, the @logto/core package reflects SAML RelayState, SAMLResponse, and actionUrl parameters into an auto-submit HTML form without escaping HTML attributes, enabling script injection. This vulnerability affects the SAML application flow via crafted RelayState parameters sent through GET or POST requests to /api/saml/:id/authn. The issue is resolved in version 1.41.0.
Potential Impact
An attacker can inject and execute arbitrary scripts in the context of the Logto tenant origin after a user completes login via a crafted SAML RelayState parameter. This can lead to limited confidentiality and integrity impacts such as theft of user session data or manipulation of the user interface. The CVSS score is 6.1 (medium severity), reflecting network attack vector, low complexity, no privileges required, user interaction required, and partial confidentiality and integrity impact.
Mitigation Recommendations
This vulnerability is fixed in logto version 1.41.0. Users should upgrade to version 1.41.0 or later to remediate the issue. No vendor advisory or official patch link is provided, but the fix is stated in the description. There is no indication that this is a cloud service; therefore, manual upgrade is required. Patch status is confirmed by the version fix information.
CVE-2026-54714: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in logto-io logto
Description
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.
CVSS v3.1
Score 6.1medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Logto versions before 1.41.0 contain a reflected cross-site scripting vulnerability due to improper neutralization of input during web page generation. Specifically, the @logto/core package reflects SAML RelayState, SAMLResponse, and actionUrl parameters into an auto-submit HTML form without escaping HTML attributes, enabling script injection. This vulnerability affects the SAML application flow via crafted RelayState parameters sent through GET or POST requests to /api/saml/:id/authn. The issue is resolved in version 1.41.0.
Potential Impact
An attacker can inject and execute arbitrary scripts in the context of the Logto tenant origin after a user completes login via a crafted SAML RelayState parameter. This can lead to limited confidentiality and integrity impacts such as theft of user session data or manipulation of the user interface. The CVSS score is 6.1 (medium severity), reflecting network attack vector, low complexity, no privileges required, user interaction required, and partial confidentiality and integrity impact.
Mitigation Recommendations
This vulnerability is fixed in logto version 1.41.0. Users should upgrade to version 1.41.0 or later to remediate the issue. No vendor advisory or official patch link is provided, but the fix is stated in the description. There is no indication that this is a cloud service; therefore, manual upgrade is required. Patch status is confirmed by the version fix information.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-15T22:58:06.564Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a51500968715ace431e0b9e
Added to database: 07/10/2026, 20:03:21 UTC
Last enriched: 07/18/2026, 15:28:08 UTC
Last updated: 08/24/2026, 22:52:12 UTC
Views: 49
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