CVE-2026-46552

NocoDB is software for building databases as spreadsheets. Prior to 2026.04.1, shared-base sessions were granted the same base-member capabilities as authenticated viewers. Using only the shared-base UUID (xc-shared-base-id), an attacker could enumerate base members and invite an arbitrary email into the base as a real member. The invited user could then redeem the invite via the normal signup flow and retain authenticated access even after the owner revoked the shared link. Shared-base sessions were mapped to ProjectRoles.VIEWER in packages/nocodb/src/strategies/base-view.strategy/base-view.strategy.ts, and packages/nocodb/src/utils/acl.ts granted baseUserList and userInvite to that role. The shared frontend (packages/nc-gui/composables/useApi/interceptors.ts) deliberately removed auth headers in favour of the shared-base header, but the ACL middleware did not distinguish shared sessions from genuine viewers. This vulnerability is fixed in 2026.04.1.

NocoDB is software for building databases as spreadsheets. Prior to 2026.04.1, shared-base sessions were granted the same base-member capabilities as authenticated viewers. Using only the shared-base UUID (xc-shared-base-id), an attacker could enumerate base members and invite an arbitrary email into the base as a real member. The invited user could then redeem the invite via the normal signup flow and retain authenticated access even after the owner revoked the shared link. Shared-base sessions were mapped to ProjectRoles.VIEWER in packages/nocodb/src/strategies/base-view.strategy/base-view.strategy.ts, and packages/nocodb/src/utils/acl.ts granted baseUserList and userInvite to that role. The shared frontend (packages/nc-gui/composables/useApi/interceptors.ts) deliberately removed auth headers in favour of the shared-base header, but the ACL middleware did not distinguish shared sessions from genuine viewers. This vulnerability is fixed in 2026.04.1.

Summary

Shared-base sessions were granted the same base-member capabilities as authenticated viewers. Using only the shared-base UUID (xc-shared-base-id), an attacker could enumerate base members and invite an arbitrary email into the base as a real member. The invited user could then redeem the invite via the normal signup flow and retain authenticated access even after the owner revoked the shared link.

Details

Shared-base sessions were mapped to ProjectRoles.VIEWER in packages/nocodb/src/strategies/base-view.strategy/base-view.strategy.ts, and packages/nocodb/src/utils/acl.ts granted baseUserList and userInvite to that role. The shared frontend (packages/nc-gui/composables/useApi/interceptors.ts) deliberately removed auth headers in favour of the shared-base header, but the ACL middleware did not distinguish shared sessions from genuine viewers.

The end-to-end chain:

• GET /api/v2/meta/bases/:baseId/users returned the member list to shared-base callers (@Acl('baseUserList')).
• POST /api/v2/meta/bases/:baseId/users accepted an invite from shared-base callers (@Acl('userInvite')); base-users.service.ts inserted a real nc_users_v2 row with invite_token and a nc_base_users_v2 row for the target base, with invited_by = null.
• The invited account redeemed the invite through the normal signup path (users.service.ts), gaining a persistent JWT scoped to the base.
• Revoking the shared link did not affect the redeemed account.

Impact

• Confidentiality: shared-base link exposes member email addresses.
• Integrity: shared-base link can mutate base ACL state by creating new members.
• Persistence: link-based access converts into durable authenticated access that survives revocation of the share.

Credit

This issue was reported by @0xmrma.

NocoDB is software for building databases as spreadsheets. Prior to 2026.04.1, shared-base sessions were granted the same base-member capabilities as authenticated viewers. Using only the shared-base UUID (xc-shared-base-id), an attacker could enumerate base members and invite an arbitrary email into the base as a real member. The invited user could then redeem the invite via the normal signup flow and retain authenticated access even after the owner revoked the shared link. Shared-base sessions were mapped to ProjectRoles.VIEWER in packages/nocodb/src/strategies/base-view.strategy/base-view.strategy.ts, and packages/nocodb/src/utils/acl.ts granted baseUserList and userInvite to that role. The shared frontend (packages/nc-gui/composables/useApi/interceptors.ts) deliberately removed auth headers in favour of the shared-base header, but the ACL middleware did not distinguish shared sessions from genuine viewers. This vulnerability is fixed in 2026.04.1.

NocoDB is software for building databases as spreadsheets. Prior to 2026.04.1, shared-base sessions were granted the same base-member capabilities as authenticated viewers. Using only the shared-base UUID (xc-shared-base-id), an attacker could enumerate base members and invite an arbitrary email into the base as a real member. The invited user could then redeem the invite via the normal signup flow and retain authenticated access even after the owner revoked the shared link. Shared-base sessions were mapped to ProjectRoles.VIEWER in packages/nocodb/src/strategies/base-view.strategy/base-view.strategy.ts, and packages/nocodb/src/utils/acl.ts granted baseUserList and userInvite to that role. The shared frontend (packages/nc-gui/composables/useApi/interceptors.ts) deliberately removed auth headers in favour of the shared-base header, but the ACL middleware did not distinguish shared sessions from genuine viewers. This vulnerability is fixed in 2026.04.1.

Summary

Shared-base sessions were granted the same base-member capabilities as authenticated viewers. Using only the shared-base UUID (xc-shared-base-id), an attacker could enumerate base members and invite an arbitrary email into the base as a real member. The invited user could then redeem the invite via the normal signup flow and retain authenticated access even after the owner revoked the shared link.

Details

Shared-base sessions were mapped to ProjectRoles.VIEWER in packages/nocodb/src/strategies/base-view.strategy/base-view.strategy.ts, and packages/nocodb/src/utils/acl.ts granted baseUserList and userInvite to that role. The shared frontend (packages/nc-gui/composables/useApi/interceptors.ts) deliberately removed auth headers in favour of the shared-base header, but the ACL middleware did not distinguish shared sessions from genuine viewers.

The end-to-end chain:

• GET /api/v2/meta/bases/:baseId/users returned the member list to shared-base callers (@Acl('baseUserList')).
• POST /api/v2/meta/bases/:baseId/users accepted an invite from shared-base callers (@Acl('userInvite')); base-users.service.ts inserted a real nc_users_v2 row with invite_token and a nc_base_users_v2 row for the target base, with invited_by = null.
• The invited account redeemed the invite through the normal signup path (users.service.ts), gaining a persistent JWT scoped to the base.
• Revoking the shared link did not affect the redeemed account.

Impact

• Confidentiality: shared-base link exposes member email addresses.
• Integrity: shared-base link can mutate base ACL state by creating new members.
• Persistence: link-based access converts into durable authenticated access that survives revocation of the share.

Credit

This issue was reported by @0xmrma.