---
id: CVE-2026-16141
title: >-
  OpenBMC's IPMI implementation, phosphor-net-ipmid, contains a logic flaw in
  which an unauthenticated client can force the RAKP Message 1 handler to return
  before it overwrites the authentication object's constructor defaults
summary: >-
  OpenBMC's IPMI implementation, phosphor-net-ipmid, contains a logic flaw in
  which an unauthenticated client can force the RAKP Message 1 handler to return
  before it overwrites the authentication object's constructor defaults. The
  IPMI se…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-457
  - CWE-798
vendor: OpenBMC
product: phosphor-net-ipmid
affected:
  - phosphor-net-ipmid <= ba6efc502e6b1fabb8ed1ca677ae5eedd64b6361
published: '2026-09-15'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:30:42.730'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-16141'
references:
  - url: >-
      https://www.runzero.com/advisories/openbmc-ipmi-auth-bypass-rakp-cve-2026-16141/
    label: 44488dab-36db-4358-99f9-bc116477f914
  - url: 'https://www.runzero.com/blog/lights-out-exposed/'
    label: 44488dab-36db-4358-99f9-bc116477f914
tags:
  - nvd
  - cve.org
epss: 0.00391
epssPercentile: 0.33049
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-15T14:59:02.838838Z'
ingestedAt: '2026-09-15T14:38:16.196Z'
---

## Overview

OpenBMC's IPMI implementation, phosphor-net-ipmid, contains a logic flaw in which an unauthenticated client can force the RAKP Message 1 handler to return before it overwrites the authentication object's constructor defaults. The IPMI service then accepts a RAKP Message 3 whose HMAC is computed with the constant 20-byte 'userKey' initialized from the string '0penBmc' and an often-predictable 'bmcRandomNum'. Several downstream vendors implement phosphor-net-ipmid as their IPMI stack, such as NVIDIA and H3C.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.