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TI-2026-40912 Aliases CVE-2026-56739

Logto: SSRF via Webhooks and Custom OAuth2 Connector UserInfo Endpoint

Priority LOW 37CWE-918Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.43.0, Logto fetches administrator-controlled outbound destinations without validating the address used for the connection. Webhook delivery in packages/core/src/libraries/hook/utils.ts can reach special-use and cloud metadata addresses. Custom OAuth2 connectors can use an attacker-selected userInfoEndpoint and forward the OAuth access token in the Authorization header, while OIDC connectors can fetch an attacker-selected jwksUri. The affected operations require tenant administrative configuration access, but they cross the server's network boundary and can expose internal data or upstream provider credentials. This issue is fixed in version 1.43.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00296 22nd percentileScored 2026-11-07
Fix Fixed logto (logto-io): 1.43.0

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 1.43.01.43.0Patch availableCNA
  • logto Vendorlogto-io Affected before 1.43.0 Fixed in 1.43.0 Patch available CNA

Remediation

  • Fix · CNA logto (logto-io) Fixed in 1.43.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56739

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