CVE-2026-55789
HIGHLogto: SAML IdP injects user-controlled profile attributes raw into signed assertions, allowing privilege escalation at relying Service Providers
Title source: cnaDescription
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.
References (4)
Core 4
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/logto-io/logto/commit/9097054860f0d638d90778d3dcde2ba050b844b6
X_Refsource_Misc x_refsource_misc
https://github.com/logto-io/logto/releases/tag/v1.41.0
X_Refsource_Confirm x_refsource_confirm
https://github.com/logto-io/logto/security/advisories/GHSA-vfpw-vq44-4p63
X_Refsource_Misc x_refsource_misc
https://github.com/logto-io/logto/pull/9107
Scores
CVSS v3
8.5
EPSS
0.0030
EPSS Percentile
22.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-91
Status
published
Products (1)
logto-io/logto
< 1.41.0
Published
Jul 10, 2026
Tracked Since
Jul 11, 2026