CVE-2026-55789 Code injection in logto
Authenticated users can inject XML into SAML attributes to escalate privileges at relying Service Providers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-55789?
CVE-2026-55789 is a high-severity code injection vulnerability in logto-io logto, published on 10 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-55789?
How do I fix CVE-2026-55789?
No fix has been published for CVE-2026-55789 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-55789 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55789 exists.
Sources
Also known as GHSA-vfpw-vq44-4p63.