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Review reviewHigh

CVE-2026-53109

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: powerpc/pgtable-frag: Fix bad page state in pte_frag_destroy powerpc uses pt_frag_refcount as a reference counter for tracking it's pte and pmd page table fragments. For PTE table, in case of Hash with 64K pagesize, we have 16 fragments of 4K size in one 64K page. Patch series [1] "mm: free retracted page table by RCU" added pte_free_defer() to defer the freeing of PTE tables when retract_page_tables() is called for madvise MADV_COLLAPSE on shmem range. [1]: https://lore.kernel.org/all/7cd843a9-aa80-14f-5eb2-33427363c20@goo...

CVSS
7.8
EPSS
0.13%
2.75% percentile
CISA KEV
Not listed
Published
2026.06.25
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.13%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: powerpc/pgtable-frag: Fix bad page state in pte_frag_destroy powerpc uses pt_frag_refcount as a reference counter for tracking it's pte and pmd page table fragments. For PTE table, in case of Hash with 64K pagesize, we have 16 fragments of 4K size in one 64K page. Patch series [1] "mm: free retracted page table by RCU" added pte_free_defer() to defer the freeing of PTE tables when retract_page_tables() is called for madvise MADV_COLLAPSE on shmem range. [1]: https://lore.kernel.org/all/7cd843a9-aa80-14f-5eb2-33427363c20@goo...

Affected product and versions

Product
Linux Linux, linux kernel
Affected versions
>= 32cc0b7c9d508efde8946a82eb3c4acfa8dfed15 < c8b710655012a2993a9567873fb71a8a51f8459c, >= 32cc0b7c9d508efde8946a82eb3c4acfa8dfed15 < a32db6fca3c74b4eb8bae5470f0680deb4cbac6f, >= 32cc0b7c9d508efde8946a82eb3c4acfa8dfed15 < fda4d71651f71c44b35829d13f3c8bf920032f77, >= 6.6, >= 6.6 < 6.18.33, >= 6.19 < 7.0.10
Fixed versions
6.18.33, 7.0.10

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, 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