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NVD / CVE Program· CNA Linux

CVE-2026-31466: mm/huge_memory: fix folio isn't locked in softleaf_to_folio()

Noroxi assessment

Priority: Monitor (action score 18/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.09% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 426ee10711586617da869c8bb798214965337617, 4c5e7f0fcd592801c9cc18f29f80fbee84eb8669, 722cfaf6b31d31123439e67b5deac6b1261a3dea.

Low priority for now. Upgrade to Linux Linux 426ee10711586617da869c8bb798214965337617, 4c5e7f0fcd592801c9cc18f29f80fbee84eb8669, 722cfaf6b31d31123439e67b5deac6b1261a3dea or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: fix folio isn't locked in softleaf_to_folio() On arm64 server, we found folio that get from migration entry isn't locked in softleaf_to_folio(). This issue triggers when mTHP splitting and zap_nonpresent_ptes() races, and the root cause is lack of memory barrier in softleaf_to_folio(). The race is as follows: CPU0 CPU1 deferred_split_scan() zap_nonpresent_ptes() lock folio split_folio() unmap_folio() change ptes to migration entries __split_folio_to_order() softleaf_to_folio() set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry)) smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio)) prep_compound_page() for tail pages In __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages are visible before the tail page becomes non-compound. smp_wmb() should be paired with smp_rmb() in softleaf_to_folio(), which is missed. As a result, if zap_nonpresent_ptes() accesses migration entry that stores tail pfn, softleaf_to_folio() may see the updated compound_head of tail page before page->flags. This issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio() because of the race between folio split and zap_nonpresent_ptes() leading to a folio incorrectly undergoing modification without a folio lock being held. This is a BUG_ON() before commit 93976a20345b ("mm: eliminate further swapops predicates"), which in merged in v6.19-rc1. To fix it, add missing smp_rmb() if the softleaf entry is migration entry in softleaf_to_folio() and softleaf_to_page(). [tujinjiang@huawei.com: update function name and comments]

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Apr 22, 2026
Updated
Nov 5, 2026
EPSS
0.0% · 0th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.0%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.5 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.168
  • linux linux kernel6.2 and later · before 6.6.134
  • linux linux kernel6.7 and later · before 6.12.81
  • linux linux kernel6.13 and later · before 6.18.21
  • linux linux kernel6.19 and later · before 6.19.11
  • linux linux kernel7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.5affected
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before 426ee10711586617da869c8bb798214965337617affected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before f1acf5887c2bbaf998dc3fe32c72b7a8b84a3dddaffected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before 722cfaf6b31d31123439e67b5deac6b1261a3deaaffected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before 7ddcf4a245c1c5a91fdd9698757e3d95179ffe41affected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before b8c49ad888892ad7b77062b9c102b799a3e9b4f8affected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before 7ad1997b9bc8032603df8f091761114479285769affected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before 8bfb8414e9f2ce6f5f2f0e3d0da52f2d132128e7affected · git
    • e9b61f19858a5d6c42ce2298cf138279375d0d9b and later · before 4c5e7f0fcd592801c9cc18f29f80fbee84eb8669affected · git
    • before 4.5not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.11-16.19.11-1
openSUSE:Leap 16.0dtb-aarch64before 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-64kbbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-azurebefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-defaultbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-default-basebefore 6.12.0-160000.36.1.160000.2.176.12.0-160000.36.1.160000.2.17
openSUSE:Leap 16.0kernel-docsbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-kvmsmallbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-obs-buildbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-obs-qabefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-rtbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-sourcebefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-symsbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-zfcpdumpbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7_Update_18before 1-150700.15.3.11-150700.15.3.1
SUSE:Linux Enterprise Live Patching 15 SP7kernel-livepatch-SLE15-SP7-RT_Update_17before 1-150700.1.3.11-150700.1.3.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-64kbbefore 6.4.0-150700.53.66.16.4.0-150700.53.66.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-defaultbefore 6.4.0-150700.53.66.16.4.0-150700.53.66.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-default-basebefore 6.4.0-150700.53.66.1.150700.17.39.16.4.0-150700.53.66.1.150700.17.39.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-sourcebefore 6.4.0-150700.53.66.16.4.0-150700.53.66.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7kernel-zfcpdumpbefore 6.4.0-150700.53.66.16.4.0-150700.53.66.1
SUSE:Linux Enterprise Module for Development Tools 15 SP7kernel-docsbefore 6.4.0-150700.53.66.26.4.0-150700.53.66.2

+23

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31462Apr 22, 2026 · drm/amdgpu: prevent immediate PASID reuse case
    22Monitor
  • ← EarlierCVE-2026-31464Apr 22, 2026 · scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done()
    32Monitor
  • Later →CVE-2026-31468Apr 22, 2026 · vfio/pci: Fix double free in dma-buf feature
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux426ee10711586617da869c8bb798214965337617Vendor (CNA)
Linux Linux4c5e7f0fcd592801c9cc18f29f80fbee84eb8669Vendor (CNA)
Linux Linux722cfaf6b31d31123439e67b5deac6b1261a3deaVendor (CNA)
Linux Linux7ad1997b9bc8032603df8f091761114479285769Vendor (CNA)
Linux Linux7ddcf4a245c1c5a91fdd9698757e3d95179ffe41Vendor (CNA)
Linux Linux8bfb8414e9f2ce6f5f2f0e3d0da52f2d132128e7Vendor (CNA)
Linux Linuxb8c49ad888892ad7b77062b9c102b799a3e9b4f8Vendor (CNA)
Linux Linuxf1acf5887c2bbaf998dc3fe32c72b7a8b84a3dddVendor (CNA)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch646.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-64kb6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-azure6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default-base6.12.0-160000.36.1.160000.2.17 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-docs6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-kvmsmall6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-build6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-qa6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-rt6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-source6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-syms6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:kernel-64kb6.12.0-160000.36.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-azure6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-default6.4.0-49.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-default-base6.12.0-160000.36.1.160000.2.17 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-docs6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-kvmsmall6.4.0-49.1 · SUSE:Linux Micro 6.0Package registry (OSV)
suse:kernel-obs-build6.12.0-160000.36.1 · SUSE:Linux Micro Extras 6.2Package registry (OSV)
suse:kernel-obs-qa6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-rt6.4.0-49.1 · SUSE:Linux Micro 6.0Package registry (OSV)

+3

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (10 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records