Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check)

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 2.6.0, UpdateUser in backend/api/handlers/users.go sets PasswordHash for any target without comparing caller and target privilege. A holder of delegated users:update permission can submit a password change for the global administrator, replace the administrator password, and authenticate as that account, resulting in complete global administrator account takeover. This issue is fixed in version 2.6.0.

Source published

16 Oct 2026 21:13:16 UTC

Source modified

19 Oct 2026 14:34:05 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 2.6.0, UpdateUser in backend/api/handlers/users.go sets PasswordHash for any target without comparing caller and target privilege. A holder of delegated users:update permission can submit a password change for the global administrator, replace the administrator password, and authenticate as that account, resulting in complete global administrator account takeover. This issue is fixed in version 2.6.0.

Source published

Oct 16, 2026, 9:13:16 PM (timezone not stated)

Source modified

Oct 19, 2026, 2:34:05 PM (timezone not stated)

Observed here

7 Nov 2026 15:27:09 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 2.6.0, UpdateUser in backend/api/handlers/users.go sets PasswordHash for any target without comparing caller and target privilege. A holder of delegated users:update permission can submit a password change for the global administrator, replace the administrator password, and authenticate as that account, resulting in complete global administrator account takeover. This issue is fixed in version 2.6.0.

Source published

16 Oct 2026 22:18:58 UTC

Source modified

19 Oct 2026 15:17:09 UTC

Observed here

25 Oct 2026 16:19:28 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

## Summary A user holding the delegated `users:update` permission can reset the global administrator's password and take over the admin account. `UpdateUser` sets the target user's `PasswordHash` from the request body for ANY target with no comparison of caller-vs-target privilege. Because role assignment and role CRUD are deliberately gated by `RequireGlobalAdmin`, `users:update` is intended to sit BELOW admin (profile management); this finding defeats that separation. ## Root Cause `UpdateUser` (handler `backend/api/handlers/users.go:317-323`) loads the target by ID and sets `userModel.PasswordHash` from the request body for any user, then `userService.UpdateUser` (`user_service.go:174`) simply `tx.Save`s — with NO actor-vs-target privilege comparison. The only `IsGlobalAdmin` guard (`user_service.go:345`) is a last-admin check inside `DeleteUser`, not the update path. Role assignment / role CRUD are `RequireGlobalAdmin` (`backend/pkg/authz/permissions.go:27-33`), proving `users:update` is intended below admin. ## Impact Complete administrator account takeover (C:H/I:H/A:H) by any holder of the delegated `users:update` permission. ## Proof of Concept 1. Admin delegates a custom "User Manager" role with `users:update`. 2. `PUT /users/{adminId}` with `{"password":"attacker123"}`. 3. `POST /auth/login {"username":"arcane","password":"attacker123"}` → admin session. ## Attack Chain 1. Action: admin delegates custom role with `users:update`. Guard: role creation is `RequireGlobalAdmin`. Bypass: intended delegation (holder is meant to manage profiles, not seize admin). 2. Action: `PUT /users/{adminId}` `{"password":"attacker123"}`. Guard: `RequirePermission(users:update)` (`users.go:154`). Bypass: holder has it; no hierarchy check (`users.go:317-323`, `user_service.go:174` unconditional Save). 3. Action: `POST /auth/login` as admin → admin session. ## Bypass Evidence - `users.go:317-323` sets `PasswordHash` for any target; `user_service.go:174-194` has no actor/target privilege comparison. - Only `IsGlobalAdmin` hits are `DeleteUser`'s last-admin guard and DTO flags (grep). - `users:update` is org-level, held by no built-in non-admin role (`permissions.go:24`). ## Affected Versions `<= 2.5.0`. Reported by **zx (Jace)** — GitHub: @manus-use

Source published

16 Oct 2026 21:15:03 UTC

Source modified

19 Oct 2026 21:40:44 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Publisher rating · HIGH

Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check) in github.com/getarcaneapp/arcane/backend

Source published

19 Oct 2026 21:08:35 UTC

Source modified

19 Oct 2026 21:31:38 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.