CVE-2026-31590

Medium

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION Drop the WARN in sev_pin_memory() on npages overflowing an int, as the WARN is comically trivially to trigger from userspace, e.g. by doing: struct kvm_enc_region range = { .addr = 0, .size = -1ul, }; __vm_ioctl(vm, KVM_MEMORY_ENCRYPT_REG_REGION, &range); Note, the checks in sev_mem_enc_register_region() that presumably exist to verify the incoming address+size are completely worthless, as both "addr" and "size" are u64s and SEV is 64-bit only, i.e. they _can't_ be greater than ULONG_MAX. That wart will be cleaned up in the near future. if (range->addr > ULONG_MAX || range->size > ULONG_MAX) return -EINVAL; Opportunistically add a comment to explain why the code calculates the number of pages the "hard" way, e.g. instead of just shifting @ulen.

Package Linux Kernel
Published 2026-04-24
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 5.9 and later are affected. Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1, 7.1-rc1 and their respective stable series.

Affected from
≥ 5.9
Fixed in
✓ 5.10.258 5.10.x ✓ 5.15.209 5.15.x ✓ 6.1.175 6.1.x ✓ 6.6.136 6.6.x ✓ 6.12.83 6.12.x ✓ 6.18.24 6.18.x ✓ 6.19.14 6.19.x ✓ 7.0.1 7.0.x ✓ 7.1-rc1

References

The following references provide additional information about CVE-2026-31590 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

9 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31590?

    CVE-2026-31590 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.9 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-31590 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31590?

    CVE-2026-31590 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-31590?

    Yes — CVE-2026-31590 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 5.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31590 actively exploited?

    No — CVE-2026-31590 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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