CVE-2026-98400

Crash-recovery disruption via missing IPL parameter block

Published Oct 14, 2026 · Updated Oct 14, 2026

NULL dereference in Linux s390 IPL handling allows attackers to disrupt crash recovery via boot without an IPL parameter block. machine_crash_shutdown() unconditionally calls set_os_info_reipl_block(), which dereferences the NULL reipl_block_actual pointer for IPL_TYPE_UNKNOWN. The path requires kdump and an absent boot parameter block, as with HMC FTP or QEMU direct kernel boot; readable lowcore at address zero can mask the fault, and attacker control of these preconditions is undocumented.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL dereference in Linux s390 IPL handling allows attackers to disrupt crash recovery via boot without an IPL parameter block. machine_crash_shutdown() unconditionally calls set_os_info_reipl_block(), which dereferences the NULL reipl_block_actual pointer for IPL_TYPE_UNKNOWN. The path requires kdump and an absent boot parameter block, as with HMC FTP or QEMU direct kernel boot; readable lowcore at address zero can mask the fault, and attacker control of these preconditions is undocumented.

The record

CVE
CVE-2026-98400
Published
Oct 14, 2026
Updated
Oct 14, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 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=3b9678472bab86ae654cf2c18d5dd551558045be <030e88812435fc5d6aa42eee41fa77b5ea620327
  2. Affected versionversion=3b9678472bab86ae654cf2c18d5dd551558045be <50f9c40768e84f30d374235b3ee3850a94d9ac29
  3. Affected versionversion=3b9678472bab86ae654cf2c18d5dd551558045be <7f918871112e8e7c581e99eb8e545af4e59c8367
  4. Affected versionversion=3b9678472bab86ae654cf2c18d5dd551558045be <92d0829eae257544b6b0faccb6e7079c45e22d48
  5. Affected versionversion=3b9678472bab86ae654cf2c18d5dd551558045be <b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd
  6. Affected versionversion=4.17

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=3b9678472bab86ae654cf2c18d5dd551558045be <030e88812435fc5d6aa42eee41fa77b5ea620327; version=3b9678472bab86ae654cf2c18d5dd551558045be <50f9c40768e84f30d374235b3ee3850a94d9ac29; version=3b9678472bab86ae654cf2c18d5dd551558045be <7f918871112e8e7c581e99eb8e545af4e59c8367; version=3b9678472bab86ae654cf2c18d5dd551558045be <92d0829eae257544b6b0faccb6e7079c45e22d48; version=3b9678472bab86ae654cf2c18d5dd551558045be <b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd; version=4.17

Published CVSS scores

No CVSS assessment is available in this record.

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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