---
id: CVE-2026-55789
title: 'Logto is the modern, open-source auth infrastructure for SaaS and AI apps'
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 s…
severity: high
cvss: 8.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N'
cwe:
  - CWE-91
published: '2026-07-10'
updated: '2026-07-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55789'
references:
  - url: >-
      https://github.com/logto-io/logto/commit/9097054860f0d638d90778d3dcde2ba050b844b6
    label: security-advisories@github.com
  - url: 'https://github.com/logto-io/logto/pull/9107'
    label: security-advisories@github.com
  - url: 'https://github.com/logto-io/logto/releases/tag/v1.41.0'
    label: security-advisories@github.com
  - url: 'https://github.com/logto-io/logto/security/advisories/GHSA-vfpw-vq44-4p63'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00402
epssPercentile: 0.31722
ingestedAt: '2026-07-11T20:15:26.699Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.