CVE-2026-55789

Logto: SAML IdP injects user-controlled profile attributes raw into signed assertions, allowing privilege escalation at relying Service Providers

State
Published
Severity
8.5 High
Published
Jul 10, 2026
Updated
Jul 13, 2026
Reserved
Jun 17, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.18.5 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:NGitHub_M

Weaknesses

  • CWE-91 XML Injection (aka Blind XPath Injection)
  • CWE-1395 Dependency on Vulnerable Third-Party Component

Affected Products

ProductVersions
logtologto-io
  • < 1.41.0Affected

References

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