OpenBMC IPMI Authentication Bypass via Default userKey and Stale Challenge Value (CVE-2026-16141) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-16141

OpenBMC IPMI Authentication Bypass via Default userKey and Stale Challenge Value

Answer in brief

CVE-2026-16141 records a Unknown severity vulnerability in OpenBMC IPMI Authentication Bypass via Default userKey and Stale Challenge Value. The current sources do not mark it as known exploited. The current feed maps OpenBMC/phosphor-net-ipmid (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2026Updated Sep 15, 2026Source checked Sep 15, 2026First seen by HOL Sep 15, 2026Material review Sep 15, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps OpenBMC/phosphor-net-ipmid (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
OpenBMC/phosphor-net-ipmidgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for OpenBMC/phosphor-net-ipmid.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.