CVE-2026-63203: Logto is the modern, open-source auth infrastructure for SaaS and AI apps.

Logto is the modern, open-source auth infrastructure for SaaS and AI apps.

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.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses logto, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.31%, higher than 23% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

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Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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