CVE-2026-31568
HighIn the Linux kernel, the following vulnerability has been resolved: s390/mm: Add missing secure storage access fixups for donated memory There are special cases where secure storage access exceptions happen in a kernel context for pages that don't have the PG_arch_1 bit set. That bit is set for non-exported guest secure storage (memory) but is absent on storage donated to the Ultravisor since the kernel isn't allowed to export donated pages. Prior to this patch we would try to export the page by calling arch_make_folio_accessible() which would instantly return since the arch bit is absent signifying that the page was already exported and no further action is necessary. This leads to secure storage access exception loops which can never be resolved. With this patch we unconditionally try to export and if that fails we fixup.
CVSS 3.1 score
7.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Weakness type
CWE-125CVE-2026-31568 is a Out-of-bounds Read vulnerability
What is Out-of-bounds Read?
The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.7
and later are affected. Fixed in
6.18.21,
6.19.11,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-31568 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/43ac2d18db1131df0a89993f709131ebfc29f3bd
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PatchKernel patch commithttps://git.kernel.org/stable/c/b00be77302d7ec4ad0367bb236494fce7172b730
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PatchKernel patch commithttps://git.kernel.org/stable/c/b36b0e804aee5f20c6798dbeaeaa7cfdb7c6cf88
Frequently asked questions
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What is CVE-2026-31568?
CVE-2026-31568 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 5.7 onward and has been patched in 6.18.21, 6.19.11 and 7.0. CVE-2026-31568 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-31568?
CVE-2026-31568 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. -
Is there a patch available for CVE-2026-31568?
Yes — CVE-2026-31568 has been patched. Fixed versions include 6.18.21, 6.19.11 and 7.0. If you are running Linux kernel 5.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-31568 actively exploited?
No — CVE-2026-31568 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Out-of-bounds Read (CWE-125)?
The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →