Power System Insufficient Entropy

published 2026-08-19 2 mo ago modified 2026-08-25 2 mo ago also EUVD-2026-62845

cvss: 5.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits: 0; none known

IBM PowerVM Hypervisor Platform KeyStore (PKS) and virtual TPM FW1110.00 through FW1110.20, FW1060.00 through FW1060.71, and FW950.00 through FW950.H2 use persistent storage key seeds that result in an AES key with reduced strength. An attacker with access to the service processor or HMC could exploit this weakness to derive the encryption key and access the data.

Patch / fix

fixed in 20 links 1

ibm power_system_s1122_(9824-22a)_firmware fw1110.30
ibm power_system_s1124_(9824-42a)_firmware fw1110.30
ibm power_system_s1122s_(9824-22b)_firmware fw1110.30
ibm power_system_s1114_(9824-41b)_firmware fw1110.30
ibm power_system_l1122_(9856-22h)_firmware fw1110.30
ibm power_system_l1124_(9856-42h)_firmware fw1110.30
ibm power_system_e1150_(9043-mru)_firmware fw1110.30
ibm power_system_e1080_(9080-hex)_firmware fw1060.72
ibm power_system_s1022_(9105-22a)_firmware fw1060.72
ibm power_system_s1024_(9105-42a)_firmware fw1060.72
ibm power_system_s1022s_(9105-22b)_firmware fw1060.72
ibm power_system_s1014_(9105-41b)_firmware fw1060.72
ibm power_system_l1022_(9786-22h)_firmware fw1060.72
ibm power_system_l1024_(9786-42h)_firmware fw1060.72
ibm power_system_e1050_(9043-mrx)_firmware fw1060.72
ibm power_system_s1012_(9028-21b)_firmware fw1060.72
ibm power_system_e1180_(9080-heu)_firmware fw1110.30
ibm power_system_s922_(9009-22g)_firmware fw950.h3
ibm power_system_h922_(9223-22s)_firmware fw950.h3
ibm power_system_s914_(9009-41g)_firmware fw950.h3

ibm.com/support/pages/node/7283890 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-20)

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.1	CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:C/C:H/I:N/A:N
NVD	3.1	6.2	CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

Affected products

IBM PowerVM Hypervisor

Classification

Weakness

CWE-331 Insufficient Entropy

References

ibm.com /support/pages/node/7283890
vendor-advisory, patch

Sources

CVE List CVE-2026-4936
NVD CVE-2026-4936

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary