CVE-2026-89458

Description

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.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/52b331c99baac653ca794bd8487c8ec4de8db203 https://git.kernel.org/stable/c/55f4df40178cdfede0d7ae848fbab00efa9b95c1 https://git.kernel.org/stable/c/77168af195d04b34c6de62b874624e74d64cef8d https://git.kernel.org/stable/c/8cb96cffceead3cbd0541154d7ecc5e6474edda1 https://git.kernel.org/stable/c/921ff697bb6f7067059793becf8b2d00de71ce41 https://git.kernel.org/stable/c/b0d94dd6e82df396e2254c8b0f25eff7d19c2e7f https://git.kernel.org/stable/c/c9adf8399732306dfc97b3adb4778038743e3f5e https://git.kernel.org/stable/c/cddb447c62466f3076938ce120028d7b591f9f37

Frequently Asked Questions

What is 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.

How do I check if I'm vulnerable to CVE-2026-89458? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.