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NVD / CVE Program· CNA Linux

CVE-2025-38085: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race

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: 0.16% (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 034a52b5ef57c9c8225d94e9067f3390bb33922f, 1013af4f585fccc4d3e5c5824d174de2257f7d6d, 952596b08c74e8fe9e2883d1dc8a8f54a37384ec.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 4.7.

Low priority for now. Upgrade to Linux Linux 034a52b5ef57c9c8225d94e9067f3390bb33922f, 1013af4f585fccc4d3e5c5824d174de2257f7d6d, 952596b08c74e8fe9e2883d1dc8a8f54a37384ec 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/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse.

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Jun 28, 2025
Updated
Aug 5, 2026
EPSS
0.1% · 5th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
4.7
CNA · Linux
7.8
3.1 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel5.11 and later · before 5.15.186
  • linux linux kernel5.16 and later · before 6.1.142
  • linux linux kernel2.6.20 and later · before 5.10.239
  • linux linux kernel6.7 and later · before 6.12.35
  • linux linux kernel6.13 and later · before 6.15.4
  • linux linux kernel6.2 and later · before 6.6.95

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

    • 2.6.20affected
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before 952596b08c74e8fe9e2883d1dc8a8f54a37384ecaffected · git
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before a3d864c901a300c295692d129159fc3001a56185affected · git
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before b7754d3aa7bf9f62218d096c0c8f6c13698fac8baffected · git
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before fe684290418ef9ef76630072086ee530b92f02b8affected · git
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before 034a52b5ef57c9c8225d94e9067f3390bb33922faffected · git
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before a6bfeb97941a9187833b526bc6cc4ff5706d0ce9affected · git
    • 39dde65c9940c97fcd178a3d2b1c57ed8b7b68aa and later · before 1013af4f585fccc4d3e5c5824d174de2257f7d6daffected · git
    • before 2.6.20not affected · semver
    • 5.10.239 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.69.1.el8_104.18.0-553.69.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10
AlmaLinux:8kernel-rt-modulesbefore 4.18.0-553.69.1.rt7.410.el8_104.18.0-553.69.1.rt7.410.el8_10

+96

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-2022-50232Jun 18, 2025 · arm64: set UXN on swapper page tables
    22Monitor
  • ← EarlierCVE-2025-38083Jun 20, 2025 · net_sched: prio: fix a race in prio_tune()
    18Monitor
  • Later →CVE-2025-38084Jun 28, 2025 · mm/hugetlb: unshare page tables during VMA split, not before
    22Monitor

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 Linux034a52b5ef57c9c8225d94e9067f3390bb33922fVendor (CNA)
Linux Linux1013af4f585fccc4d3e5c5824d174de2257f7d6dVendor (CNA)
Linux Linux952596b08c74e8fe9e2883d1dc8a8f54a37384ecVendor (CNA)
Linux Linuxa3d864c901a300c295692d129159fc3001a56185Vendor (CNA)
Linux Linuxa6bfeb97941a9187833b526bc6cc4ff5706d0ce9Vendor (CNA)
Linux Linuxb7754d3aa7bf9f62218d096c0c8f6c13698fac8bVendor (CNA)
Linux Linuxfe684290418ef9ef76630072086ee530b92f02b8Vendor (CNA)
almalinux:bpftool4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.69.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.147-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch646.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-64kb6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default-base6.12.0-160000.8.1.160000.2.5 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-docs6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-kvmsmall6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-build6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-qa6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-rt6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-source6.12.0-160000.8.1 · openSUSE:Leap 16.0Package registry (OSV)

+27

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. Fix✗ → ✓

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

References

Show all references (9 more)

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

All records