Description
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.
References7
- github.com/getgrav/grav-plugin-admin2/commit/a0bf26f7e5d7a98894…
- github.com/getgrav/grav-plugin-api/commit/8071c10bc3a4743a4b8cf…
- github.com/getgrav/grav/commit/ad9709f865b09b68798fb1ac375b484a…
- github.com/getgrav/grav/security/advisories/GHSA-pc8m-jxvh-vmrc
- github.com/trilbymedia/grav-plugin-flex-objects/commit/0b384f5b…
- www.vulncheck.com/advisories/grav-through-authentication-bypass…
- github.com/getgrav/grav/security/advisories/GHSA-pc8m-jxvh-vmrc
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
8.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 59 · as of 12 November 2026
- CWE
- CWE-863
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.