CVE-2026-55789: CWE-91: XML Injection (aka Blind XPath Injection) in logto-io logto
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.
AI Analysis
Technical Summary
CVE-2026-55789 is an XML Injection (Blind XPath Injection) vulnerability in logto-io's Logto product affecting versions before 1.41.0. The self-hosted SAML IdP builds signed SAML responses by string-substituting user profile attributes into XML templates without escaping, using samlify 2.10.0. This allows an authenticated low-privilege user to inject XML markup into profile attributes, resulting in forged signed SAML attributes and potential privilege escalation at relying Service Providers. The vulnerability has a CVSS 3.1 score of 8.5 (high severity).
Potential Impact
An authenticated low-privilege user can inject XML markup into profile attributes, causing Logto to sign forged SAML attributes such as arbitrary roles. This enables privilege escalation at relying Service Providers that authorize based on SAML attributes. Confidentiality impact is low, integrity impact is high, and availability is not affected.
Mitigation Recommendations
A fix is available in Logto version 1.41.0. Users should upgrade to version 1.41.0 or later to remediate this vulnerability. No vendor advisory is provided, but the description explicitly states the issue is fixed in 1.41.0. Until upgraded, restrict access to trusted users and consider additional validation of SAML attributes at relying Service Providers.
CVE-2026-55789: CWE-91: XML Injection (aka Blind XPath Injection) in logto-io logto
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.
CVSS v3.1
Score 8.5high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-55789 is an XML Injection (Blind XPath Injection) vulnerability in logto-io's Logto product affecting versions before 1.41.0. The self-hosted SAML IdP builds signed SAML responses by string-substituting user profile attributes into XML templates without escaping, using samlify 2.10.0. This allows an authenticated low-privilege user to inject XML markup into profile attributes, resulting in forged signed SAML attributes and potential privilege escalation at relying Service Providers. The vulnerability has a CVSS 3.1 score of 8.5 (high severity).
Potential Impact
An authenticated low-privilege user can inject XML markup into profile attributes, causing Logto to sign forged SAML attributes such as arbitrary roles. This enables privilege escalation at relying Service Providers that authorize based on SAML attributes. Confidentiality impact is low, integrity impact is high, and availability is not affected.
Mitigation Recommendations
A fix is available in Logto version 1.41.0. Users should upgrade to version 1.41.0 or later to remediate this vulnerability. No vendor advisory is provided, but the description explicitly states the issue is fixed in 1.41.0. Until upgraded, restrict access to trusted users and consider additional validation of SAML attributes at relying Service Providers.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-17T14:40:28.380Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a51500b68715ace431e0c64
Added to database: 07/10/2026, 20:03:23 UTC
Last enriched: 07/18/2026, 15:28:52 UTC
Last updated: 08/23/2026, 10:52:10 UTC
Views: 106
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