Vulnerability · Published Sep 15, 2026 · Assigned by runZero

CVE-2026-16141OpenBMC IPMI Authentication Bypass via Default userKey and Stale Challenge Value

High 8.1

In plain English

A high-severity hard-coded credentials in phosphor-net-ipmid from OpenBMC. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.5%top 54.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
OpenBMC	phosphor-net-ipmid	0 – through ba6efc502e6b1fabb8ed1ca677ae5eedd64b6361

Weakness: CWE-798, CWE-457 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://www.runzero.com/advisories/openbmc-ipmi-auth-bypass-rakp-cve-2026-16141/ third-party-advisory
https://www.runzero.com/blog/lights-out-exposed/ related