CVE-2026-54714CWE-79

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

Medium · published July 10, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
26.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00338 · 26.0th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-07-10T19:54Z
EPSS history
Timeline
  • 10 JUL 19:54Z
    Logto: XSS via unescaped RelayState in SAML auto-submit form
    cvelistv5