CVE-2026-89458

Stale memory exposure via failed ESE reads

Published Sep 11, 2026 · Updated Sep 11, 2026

Uninitialized-memory exposure in the Linux s390 DASD driver allows local users to receive stale data through failed ESE track reads. dasd_int_handler() marks the request successful without checking ese_read(), although early errors can leave destination pages untouched. Reachability requires an s390 system with an ESE DASD device and an NRF read entering an early error path; no write or code-execution impact is established.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized-memory exposure in the Linux s390 DASD driver allows local users to receive stale data through failed ESE track reads. dasd_int_handler() marks the request successful without checking ese_read(), although early errors can leave destination pages untouched. Reachability requires an s390 system with an ESE DASD device and an NRF read entering an early error path; no write or code-execution impact is established.

The record

CVE
CVE-2026-89458
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=5.4.26 <5.5
  2. Affected versionversion=5.5.10 <5.6
  3. Affected versionversion=5.6
  4. Affected versionversion=5e6bdd37c5526ef01326df5dabb93011ee89237e <52b331c99baac653ca794bd8487c8ec4de8db203
  5. Affected versionversion=5e6bdd37c5526ef01326df5dabb93011ee89237e <b0d94dd6e82df396e2254c8b0f25eff7d19c2e7f
  6. Affected versionversion=5e6bdd37c5526ef01326df5dabb93011ee89237e <c9adf8399732306dfc97b3adb4778038743e3f5e
  7. Affected versionversion=5e6bdd37c5526ef01326df5dabb93011ee89237e <cddb447c62466f3076938ce120028d7b591f9f37
  8. Affected versionversion=5f7c9989f11305aaa43e0f4378f4f070022a9f2b
  9. Affected versionversion=fbbacd0dcbc3ae9398c569dbea96ae4b5ad97e04

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.4.26 <5.5; version=5.5.10 <5.6; version=5.6; version=5e6bdd37c5526ef01326df5dabb93011ee89237e <52b331c99baac653ca794bd8487c8ec4de8db203; version=5e6bdd37c5526ef01326df5dabb93011ee89237e <b0d94dd6e82df396e2254c8b0f25eff7d19c2e7f; version=5e6bdd37c5526ef01326df5dabb93011ee89237e <c9adf8399732306dfc97b3adb4778038743e3f5e; version=5e6bdd37c5526ef01326df5dabb93011ee89237e <cddb447c62466f3076938ce120028d7b591f9f37; version=5f7c9989f11305aaa43e0f4378f4f070022a9f2b; version=fbbacd0dcbc3ae9398c569dbea96ae4b5ad97e04

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.

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

T1005Data from Local System

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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