CVE-2026-89456

HIGHCVSS 7/10EPSS 0.14%

Last modified

CVE-2026-89456 is a high-severity vulnerability rated 7/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Propagate partial completion length across ERP recovery dasd_default_erp_postaction() copies the timing and device state from the finished ERP request back to the original request but drops proc_bytes. A request that was partially completed, an ESE read of a not-yet-allocated track returns fewer bytes than requested, and then recovered through the ERP chain loses its partial-completion length. __dasd_cleanup_cqr() then sees proc_bytes == 0 and completes the whole request instead of requeueing the remainder, silently returning zeroed data for the part that was never read. Carry proc_bytes over to the original request like the other per-request state.. EPSS estimates a 0.14% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Propagate partial completion length across ERP recovery dasd_default_erp_postaction() copies the timing and device state from the finished ERP request back to the original request but drops proc_bytes. A request that was partially completed, an ESE read of a not-yet-allocated track returns fewer bytes than requested, and then recovered through the ERP chain loses its partial-completion length. __dasd_cleanup_cqr() then sees proc_bytes == 0 and completes the whole request instead of requeueing the remainder, silently returning zeroed data for the part that was never read. Carry proc_bytes over to the original request like the other per-request state.

Metrics

EPSS Probability
0.14%

4.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < 9e063165d3fe58db2a517717b830f17e82d03467; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < 6b0954c8a259da1e4aa745989f82723947acfb46; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < d0a2f97d8c97134aa7f6a191940b7bab4bb42f5f; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < f735b9710f0c8fe72c1060103e865f4ae678190b; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < d6b8778b1b82aa3a8dbf8612080f635b834bd16b; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < ceafb262475ac6cb3a7d07b1102608be2b216b99; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < 15ec03452c18e8d288e519837d21b308300d74b2; >= 5e6bdd37c5526ef01326df5dabb93011ee89237e, < 6fb5ba2e7e43173a3761e46f091070a8185efa14; fbbacd0dcbc3ae9398c569dbea96ae4b5ad97e04; 5f7c9989f11305aaa43e0f4378f4f070022a9f2b; >= 5.4.26, < 5.5; >= 5.5.10, < 5.6
LinuxLinux5.6

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-89456?
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Propagate partial completion length across ERP recovery dasd_default_erp_postaction() copies the timing and device state from the finished ERP request back to the original request but drops proc_bytes. A request that was partially completed, an ESE read of a not-yet-allocated track returns fewer bytes than requested, and then recovered through the ERP chain loses its partial-completion length. __dasd_cleanup_cqr() then sees proc_bytes == 0 and completes the whole request instead of requeueing the remainder, silently returning zeroed data for the part that was never read. Carry proc_bytes over to the original request like the other per-request state.
How severe is CVE-2026-89456?
CVE-2026-89456 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.
How do I fix CVE-2026-89456?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST