Summary
Open WebUI: Users denied by the OAuth role policy can still sign in via token exchange
Open WebUI's OAuth token exchange endpoint issues a session for a provider access token without running the OAuth role management that the normal OAuth login callback runs. A user whose provider roles the login callback would refuse, or would demote, could still obtain a working session at their existing role through this endpoint.
Preconditions
ENABLE_OAUTH_TOKEN_EXCHANGE=True. It is disabled by default, so a default deployment is not affected.ENABLE_OAUTH_ROLE_MANAGEMENT=Truetogether withOAUTH_ALLOWED_ROLESorOAUTH_ADMIN_ROLES. Role management is off by default, and deployments not using it are not affected.- A valid, unexpired access token on the configured provider.
- An Open WebUI account already linked to that provider subject, or an account with a matching email when
OAUTH_MERGE_ACCOUNTS_BY_EMAILis enabled. This endpoint never creates accounts, so a token for a subject with no existing account is rejected.
Root cause
The affected component is the OAuth token exchange endpoint in backend/open_webui/routers/auths.py, present in builds from 0.8.0 onward.
The endpoint was added as a second entry point into the same session-issuing path the OAuth login callback uses, but it re-implemented only the identity lookup and not the policy checks surrounding it. Role evaluation lived inside the callback's own body rather than in shared code, so the second caller inherited none of it.
Credits
@Classic298
Impact
An admin who relies on OAuth role management expects a user to lose access, or lose admin, as soon as the identity provider stops reporting the required role. The login callback does enforce this on the next sign-in. Token exchange kept issuing sessions and never re-evaluated the role, so the user retained working access as their existing account at its existing role, including an admin role the provider had already revoked. The endpoint cannot create an account and cannot raise anyone's role, so this grants continued access rather than new or elevated access.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-88006 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.11.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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d799e81ed, released in 0.11.1, runs the same role evaluation on the provider's response that the login callback runs. The exchange is denied with 403 when the reported roles match no allowed or admin role, and the account's role is updated to match the provider otherwise. Upgrading restores the check with no further action.
Frequently Asked Questions
- What is CVE-2026-88006? CVE-2026-88006 is a medium-severity incorrect authorization vulnerability in open-webui (pip), affecting versions >= 0.8.0, < 0.11.1. It is fixed in 0.11.1. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2026-88006? CVE-2026-88006 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of open-webui are affected by CVE-2026-88006? open-webui (pip) versions >= 0.8.0, < 0.11.1 is affected.
- Is there a fix for CVE-2026-88006? Yes. CVE-2026-88006 is fixed in 0.11.1. Upgrade to this version or later.
- Is CVE-2026-88006 exploitable, and should I be worried? Whether CVE-2026-88006 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-88006 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-88006? Upgrade
open-webuito 0.11.1 or later.