CVE-2026-16141 — OpenBMC IPMI Authentication Bypass via Default userKey and Stale Challenge Value
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 t…
Published: 2026-09-15 · CVSS: 8.1 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7