CVE-2026-45720
Omni has a TOCTOU race condition that allows multiple concurrent uses of a single-use SAML session token
Description
## Summary `SAML.getSession` (`internal/pkg/auth/interceptor/saml.go`) checks the `Used` flag on a `SAMLAssertion` resource and then marks it used in two separate state operations. Because the check and the update are not atomic, concurrent requests carrying the same `saml-session` token can both observe `Used == false`, both pass validation, and both return a successful authentication context. An attacker who obtains a valid `saml-session` token can exploit this window to authenticate as the token's owner multiple times, defeating the one-time-use guarantee. ## Severity - **Attack Vector:** Local: the attacker needs to either be able to intercept the local, unencrypted traffic or needs access to user's browser. - **Attack Complexity:** High: the attacker must first obtain a valid `saml-session` token belonging to the victim (requires a separate interception step; the token is ephemeral and single-use by design). - **Privileges Required:** None: no Omni account is required to carry out the race once the session token is in hand. - **User Interaction:** Required: the victim must initiate a SAML authentication flow to produce the session token that the attacker intercepts. - **Scope:** Unchanged: the impact stays within Omni's authorization boundary. - **Confidentiality Impact:** High: successful exploitation authenticates the attacker as the victim's email identity, granting read access to any resource accessible to that identity. - **Integrity Impact:** High: the attacker can confirm one or more public keys under the victim's identity (via `ConfirmPublicKey`), establishing persistent access credentials tied to the victim's account. - **Availability Impact:** High: if the attacker can successfully perform the attack and if the victim is a privileged Omni user, e.g., an Omni Operator or Admin, they can take Omni down. ## Impact - **Session replay**: A stolen `saml-session` token can be used more than once, defeating its single-use guarantee. - **Multiple public key confirmations**: An attacker who steals the session can confirm N attacker-controlled public keys under the victim's identity in a single stolen session window, creating N persistent long-lived API credentials tied to the victim's account. - **Authentication as victim**: Any gRPC endpoint gated by the SAML interceptor can be reached as the victim's email identity during the race window. - **Audit log pollution**: Each raced call generates an audit entry attributed to the victim's email, obscuring the attacker's actions. ## Credit This vulnerability was discovered and reported by [bugbunny.ai](https://bugbunny.ai).
How to fix CVE-2026-45720
To remediate CVE-2026-45720, upgrade the affected package to a fixed version below.