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TI-2026-40275 Aliases CVE-2026-55789

XML injection in logto-io logto

Priority HIGH 70CWE-1395Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's self-hosted SAML application IdP built the signed SAML response and assertion by string-substituting user-controlled profile attributes such as name, email, and custom attribute-mapping values into element-text placeholders of a SAML XML template using samlify 2.10.0, which left those placeholders unescaped. An authenticated low-privilege user could place XML markup in a profile attribute so Logto signed a forged SAML attribute, such as an arbitrary role, allowing privilege escalation at relying Service Providers that authorize on SAML attributes. This issue is fixed in version 1.41.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00344 28th percentileScored 2026-11-07
Fix Fixed logto (logto-io): 1.41.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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-2026-55789

References

Other 4

  • TI-2026-44494 Logto: ReDoS via unescaped user input in email subaddressing regex (blockSubaddressing) CVSS 3.1HIGH 7.5
  • 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
  • TI-2026-45087 logto-tunnel serves files outside --experience-path via path traversal CVSS 4.0HIGH 8.7
See all 10 →

Sources

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