CVE-2026-63203 Logto: Account API can disclose stored third-party provider tokens without the identities scope
Attackers with low-privilege tokens can retrieve stored third-party provider tokens due to missing scope checks, enabling access to upstream APIs.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-63203?
CVE-2026-63203 is a high-severity missing authorization vulnerability in logto-io logto, published on 24 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Logto is the modern, open-source auth infrastructure for SaaS and AI apps. From 1.31.0 until 1.42.0, the Account API handlers in packages/core/src/routes/account/third-party-tokens.ts allow a caller holding a same-user access token with only the openid scope to retrieve stored social or enterprise SSO provider access tokens through GET /api/my-account/identities/{target}/access-token or GET /api/my-account/sso-identities/{connectorId}/access-token. The handlers authenticate the user but do not require the identities scope that protects neighboring identity-detail operations, bypassing the intended Account API consent boundary. Exploitation requires federated token-set storage to be enabled and the affected user to have authenticated through a supported connector. A low-trust application can use the disclosed provider token against upstream APIs within that token's granted scopes. This issue is fixed in version 1.42.0.
Weakness: CWE-862
Which versions are affected by CVE-2026-63203?
How do I fix CVE-2026-63203?
No fix has been published for CVE-2026-63203 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-63203 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63203 exists.
Sources
Also known as GHSA-6g9q-qrx7-3jxf.