Frontegg SAML SSO accepts unsigned or untrusted assertions
Frontegg SAML SSO through 1.0.1 establishes WordPress sessions without verifying the signature or issuer of SAML authentication responses. An unauthenticated attacker can forge an assertion to log in as any existing user, including an administrator, or create an arbitrary account. The authoritative export does not name the assertion endpoint or mapped identity fields.
- Component
- Frontegg SAML SSO
- Plugin slug
frontegg-saml-sso- Affected
- <= 1.0.1
- Safe version
- See mitigation notes
- Published
- Sep 12, 2026
This CVE was published Sep 12, 2026 and is one of 1 known issue for this plugin.
Update, patch or deactivate.
No fixed release is confirmed in the authoritative export. Disable the plugin and use an alternate trusted login path until the vendor confirms a fix. The application-level fix must validate the XML signature, issuer, audience, recipient, timing, request correlation, and identity mapping before creating a session or account.
No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The Frontegg SAML SSO WordPress plugin through 1.0.1 does not verify the signature or issuer of SAML authentication responses before establishing a session, allowing unauthenticated attackers to log in as any user, including administrators, as well as to create arbitrary accounts.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H