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TI-2026-39528 Aliases CVE-2026-54714

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

Priority LOW 27CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00338 27th percentileScored 2026-11-07
Fix Fixed logto (logto-io): 1.41.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
logto-iologtobefore 1.41.01.41.0Patch availableCNA
  • logto Vendorlogto-io Affected before 1.41.0 Fixed in 1.41.0 Patch available CNA

Remediation

  • Fix · CNA logto (logto-io) Fixed in 1.41.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54714

References

Other 4

  • TI-2026-44494 Logto: ReDoS via unescaped user input in email subaddressing regex (blockSubaddressing) CVSS 3.1HIGH 7.5
  • TI-2026-40275 XML injection in logto-io logto CVSS 3.1HIGH 8.5
  • TI-2026-56728 Logto Server-Side Request Forgery via OIDC SSO Connector Issuer URL CVSS 4.0HIGH 8.2
  • TI-2026-39955 Logto: Account Center MFA management step-up bypass via WebAuthn registration verification CVSS 3.1HIGH 8.1
  • TI-2026-45089 Logto: Account API can disclose stored third-party provider tokens without the identities scope CVSS 3.1HIGH 7.6
  • TI-2026-45086 Logto: OS command injection vulnerability exists in the Commitlint workflow CVSS 3.1MEDIUM 6.3
See all 10 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences