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.

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.43.0, Logto fetches administrator-controlled outbound destinations without validating the address used for the connection. Webhook delivery in packages/core/src/libraries/hook/utils.ts can reach special-use and cloud metadata addresses. Custom OAuth2 connectors can use an attacker-selected userInfoEndpoint and forward the OAuth access token in the Authorization header, while OIDC connectors can fetch an attacker-selected jwksUri. The affected operations require tenant administrative configuration access, but they cross the server's network boundary and can expose internal data or upstream provider credentials. This issue is fixed in version 1.43.0.

Logto through 1.42.0 contains a server-side request forgery vulnerability in the OIDC SSO connector creation endpoint that fails to validate the issuer URL parameter. Tenant administrators with Management API credentials can supply arbitrary internal URLs to trigger HTTP GET requests to private network services, with response content returned in API responses.

Logto through 1.42.0 contains a server-side request forgery vulnerability in the POST /api/hooks/:id/test endpoint that accepts arbitrary URLs without host validation. Tenant administrators with Management API tokens can make the server issue HTTP POST requests to internal URLs and retrieve response bodies from services on the private network.

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's email subaddressing blocklist in packages/core/src/libraries/sign-in-experience/email-blocklist-policy.ts used the attacker-controlled domain from email input to construct subaddressingRegex when blockSubaddressing was enabled. The permissive emailRegEx accepted multiple at signs and regular expression metacharacters, and POST /api/experience/verification/verification-code could therefore cause catastrophic backtracking in subaddressingRegex.test(email). The resulting event-loop stall could make authentication, token issuance, SSO, and the administrative console unavailable. This issue is fixed in version 1.41.0.

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. From 1.40.1 until 1.41.0, Logto's .github/workflows/commitlint.yml directly interpolated github.event.pullrequest.title into the Commitlint on PR title step's inline echo command before piping the title to npx commitlint. A pull request title containing a single quote could terminate the echo string and append arbitrary shell commands on the GitHub Actions runner. The pullrequest trigger used a read-only GITHUBTOKEN and did not expose repository secrets, but injected commands could alter or disrupt the ephemeral workflow execution. This issue is fixed in version 1.41.0.

Logto silently fails to delete IdP-initiated SAML sessions, enabling session replay and reuse within the session’s validity window.

Logto does not enforce locally configured MFA during SSO authentication, allowing users to bypass second-factor requirements and grants unauthorized access.

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's Account Center step-up check accepted any active verification record that belonged to the current user and had isVerified === true. A WebAuthn registration verification record for binding a new passkey could be created and verified with only an existing Account API bearer token, then sent in the logto-verification-id header and treated as identityVerified=true by Account Center routes, allowing MFA factor management without proving possession of an existing password, identifier, or MFA factor. This issue is fixed in version 1.41.0.