CVE-2026-72831

Zwakheid

The Flex Objects plugin (through 1.4.6, tested with Grav 2.0.11) contains an incorrect authorization vulnerability in its Flex Objects API. FlexApiController::update() checks only the general Flex directory permission and does not apply the additional target/field/super-admin checks enforced by the dedicated Users and Groups API controllers. An authenticated account with api.access, admin.login, and users.update permissions (but without api.users.write or admin.super) can use the generic /api/v1/flex-objects/user-accounts endpoint to change a super administrator's password, or the /api/v1/flex-objects/user-groups endpoint to grant its group admin.super, resulting in full site takeover. Fixed in Flex Objects 1.4.7.

Bronnen

• https://github.com/getgrav/grav-plugin-admin2/commit/a0bf26f7e5d7a98894b7cd2b8c5afe419b264e53
• https://github.com/getgrav/grav-plugin-api/commit/8071c10bc3a4743a4b8cf003dfb1644d6680c2ea
• https://github.com/getgrav/grav/commit/ad9709f865b09b68798fb1ac375b484a8cc1d892
• https://github.com/getgrav/grav/security/advisories/GHSA-pc8m-jxvh-vmrc
• https://github.com/trilbymedia/grav-plugin-flex-objects/commit/0b384f5b0e73b1ad9dd29c70185407895ea3b09f
• https://www.vulncheck.com/advisories/grav-through-authentication-bypass-via-flex-objects