# CVE-2026-55789

## Summary

- **CVE ID:** CVE-2026-55789
- **Severity:** HIGH
- **CVSS Score:** 8.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N)
- **CWE:** CWE-91, CWE-1395
- **Published:** Jul 10, 2026
- **Last Modified:** Jul 13, 2026

## 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.

## Affected Products

- logto-io — logto (< 1.41.0)

## References

- [CNA](https://github.com/logto-io/logto/security/advisories/GHSA-vfpw-vq44-4p63)
- [CNA](https://github.com/logto-io/logto/pull/9107)
- [CNA](https://github.com/logto-io/logto/commit/9097054860f0d638d90778d3dcde2ba050b844b6)
- [CNA](https://github.com/logto-io/logto/releases/tag/v1.41.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.40%
- **EPSS Percentile:** 33.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._