CVE-2026-89458
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Do not complete a failed ESE read as successful dasd_int_handler() completes an NRF read of an unallocated ESE track by calling ese_read() and unconditionally marking the request DASD_CQR_SUCCESS. dasd_eckd_ese_read() can return an error before it has zeroed the destination buffer: a failed sense-data parse or a current track outside the requested range both return early, leaving the destination pages untouched. The request is still completed successfully, so the block layer is handed stale / uninitialized memory instead of zeros. Check the ese_read() return value and fail the request through the normal error path instead of forcing DASD_CQR_SUCCESS.
Affected versions
Linux kernel versions
5.4.26,
5.5.10,
5.6
and later are affected. Fixed in
5.10.270,
5.15.221,
6.1.188,
6.6.157,
6.12.109,
6.18.50,
7.2.4,
7.3-rc1
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-89458?
CVE-2026-89458 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.4.26 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-89458 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-89458?
Yes. CVE-2026-89458 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 5.4.26 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-89458 actively exploited?
No. CVE-2026-89458 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.