CVE-2026-96627 is a high-severity (CVSS 8.8) CWE-266 vulnerability in github.com/getarcaneapp/arcane/backend/v2. A fix is available for github.com/getarcaneapp/arcane/backend/v2 — see the affected versions and patch details below.
Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check)
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-96627.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-96627 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,415 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
github.com/getarcaneapp/arcane/backend/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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.Saves — 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
- Admin delegates a custom "User Manager" role with
users:update. PUT /users/{adminId}with{"password":"attacker123"}.POST /auth/login {"username":"arcane","password":"attacker123"}→ admin session.
Attack Chain
- Action: admin delegates custom role with
users:update. Guard: role creation isRequireGlobalAdmin. Bypass: intended delegation (holder is meant to manage profiles, not seize admin). - 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:174unconditional Save). - Action:
POST /auth/loginas admin → admin session.
Bypass Evidence
users.go:317-323setsPasswordHashfor any target;user_service.go:174-194has no actor/target privilege comparison.- Only
IsGlobalAdminhits areDeleteUser's last-admin guard and DTO flags (grep). users:updateis 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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/getarcaneapp/arcane/backend/v2 | all versions | 2.6.0go get github.com/getarcaneapp/arcane/backend/v2@v2.6.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/getarcaneapp/arcane/backend/v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/getarcaneapp/arcane/backend/v2 to 2.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-96627 is resolved across your whole dependency graph.
Workarounds
Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable.
Frequently Asked Questions
Is CVE-2026-96627 in your dependencies?
Find it across Go, including transitive dependencies.