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Review reviewHigh

CVE-2025-39776

Linux Linux, SIMATIC CN 4100, linux kernel

In the Linux kernel, the following vulnerability has been resolved: mm/debug_vm_pgtable: clear page table entries at destroy_args() The mm/debug_vm_pagetable test allocates manually page table entries for the tests it runs, using also its manually allocated mm_struct. That in itself is ok, but when it exits, at destroy_args() it fails to clear those entries with the *_clear functions. The problem is that leaves stale entries. If another process allocates an mm_struct with a pgd at the same address, it may end up running into the stale entry. This is happening in practice on a debug kernel w...

CVSS
7.8
EPSS
0.14%
3.50% percentile
CISA KEV
Not listed
Published
2025.09.12
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.14%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: mm/debug_vm_pgtable: clear page table entries at destroy_args() The mm/debug_vm_pagetable test allocates manually page table entries for the tests it runs, using also its manually allocated mm_struct. That in itself is ok, but when it exits, at destroy_args() it fails to clear those entries with the *_clear functions. The problem is that leaves stale entries. If another process allocates an mm_struct with a pgd at the same address, it may end up running into the stale entry. This is happening in practice on a debug kernel w...

Affected product and versions

Product
Linux Linux, SIMATIC CN 4100, linux kernel
Affected versions
>= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 7bf57a0709cd7c9088cea8de023d6f4fbf2518b0, >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 47d2a149611b8a94d24add9868c442a4af278658, >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 63962ff932ef359925b94be2a88df6b4fd4fed0a, >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 61a9f2e5c49f05e3ea2c16674540a075a1b4be6f, >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 561171db3b3eb759ba3f284dba7a76f4476ade03, >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < dde30854bddfb5d69f30022b53c5955a41088b33, >= 5.15, < V5.0, >= 5.15 < 5.15.190, >= 5.16 < 6.1.149, >= 6.2 < 6.6.103, >= 6.7 < 6.12.44, >= 6.13 < 6.16.4, 6.17, 11.0
Fixed versions
5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, SIMATIC CN 4100, linux kernel and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416
CVE-2025-39776 — Linux Linux, SIMATIC CN 4100, linux kernel | SECUFOCUS NOW