CVE-2026-55789

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 3.1

8.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-91

Published

2026-07-10

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

References

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

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