CyberSecBulletin
CVE-2026-16933NVD status: Analyzed

Power Systems Firmware: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2026-16933 is a high-severity integer overflow or wraparound vulnerability in Power Systems Firmware from IBM, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. Affected Power Systems Firmware versions: FW1120.00; FW1110.00 through FW1110.30; FW1060.00 through FW1060.80, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Power System S1122 (9824-22a) Firmware to fw1110.31 or a later version.
  2. Update Power System S1124 (9824-42a) Firmware to fw1110.31 or a later version.
  3. Update Power System S1122s (9824-22b) Firmware to fw1110.31 or a later version.
  4. Read the advisory on ibm.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
IBMPower Systems FirmwareFW1120.00; FW1110.00 through FW1110.30; FW1060.00 through FW1060.80; FW950.00 through FW950.H2; OP940.00 through OP940.a1; OP940.00 through OP940.81Not stated
IBMPower System S1122 (9824-22a) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System S1124 (9824-42a) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System S1122s (9824-22b) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System S1114 (9824-41b) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System L1122 (9856-22h) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System L1124 (9856-42h) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System E1150 (9043-mru) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System S1112 (9242-21b) Firmwarefw1120.00Not stated
IBMPower System S1112 (9242-21t) Firmwarefw1120.00Not stated
IBMPower System E1080 (9080-hex) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System S1022 (9105-22a) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System S1024 (9105-42a) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System S1022s (9105-22b) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System S1014 (9105-41b) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System L1022 (9786-22h) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System L1024 (9786-42h) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System E1050 (9043-mrx) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System S1012 (9028-21b) Firmwarefw1060.00 up to, but not including, fw1060.81fw1060.81
IBMPower System E1180 (9080-heu) Firmwarefw1110.00 up to, but not including, fw1110.31; fw1120.00fw1110.31
IBMPower System S922 (9009-22g) Firmwarefw950.00 up to, but not including, fw950.h3fw950.h3
IBMPower System H922 (9223-22s) Firmwarefw950.00 up to, but not including, fw950.h3fw950.h3
IBMPower System S914 (9009-41g) Firmwarefw950.00 up to, but not including, fw950.h3fw950.h3
IBMPower System S924 (9009-42g) Firmwarefw950.00 up to, but not including, fw950.h3fw950.h3
IBMPower System H924 (9223-42s) Firmwarefw950.00 up to, but not including, fw950.h3fw950.h3

Version data comes from the organisation that assigned the CVE; 5 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (us.ibm.com).

Official description

IBM Power Systems Firmware FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, FW950.00 through FW950.H2, OP940.00 through OP940.a1 (Power9), and OP940.00 through OP940.81 (Power HMC) is affected by a vulnerability in the interface between the BMC/FSP and the host system. An attacker with service account or root access to the BMC/FSP can read and write arbitrary regions of host system memory, giving full control over the host system and all hosted partitions, resulting in a confidentiality, integrity, and availability impact.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Power Systems Firmware

All Power Systems Firmware vulnerabilities

Recent Integer Overflow or Wraparound vulnerabilities

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