CVE-2026-18871

Host boot-stack crash via configuration parsing

Published Aug 19, 2026 · Updated Aug 20, 2026

Stack-based buffer overflow in IBM PowerVM Hypervisor allows local users to crash the host firmware boot stack during initialization. The host firmware configuration parser mishandles specially crafted configuration data, overflowing a stack buffer and causing possible memory corruption. Authenticated service-level access to the service processor is required; affected releases are FW1120.00, FW1110.00 through FW1110.30, and FW1060.00 through FW1060.80.

CVSS severity7.3
High
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in IBM PowerVM Hypervisor allows local users to crash the host firmware boot stack during initialization. The host firmware configuration parser mishandles specially crafted configuration data, overflowing a stack buffer and causing possible memory corruption. Authenticated service-level access to the service processor is required; affected releases are FW1120.00, FW1110.00 through FW1110.30, and FW1060.00 through FW1060.80.

The record

CVE
CVE-2026-18871
Published
Aug 19, 2026
Updated
Aug 20, 2026
Vendor
IBM
Product
PowerVM Hypervisor
Classifications
CWE-121, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=FW1060.00 <=FW1060.80
  2. Affected versionversion=FW1110.00 <=FW1110.30
  3. Affected versionversion=FW1120.00

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

IBM · PowerVM Hypervisorversion=FW1060.00 <=FW1060.80; version=FW1110.00 <=FW1110.30; version=FW1120.00

Published CVSS scores

7.3IBM CorporationCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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