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Review reviewHigh

CVE-2026-63875

Linux

In the Linux kernel, the following vulnerability has been resolved: arm64: tlb: Flush walk cache when unsharing PMD tables When huge_pmd_unshare() is called to unshare a PMD table, the tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables in th...

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.20
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: arm64: tlb: Flush walk cache when unsharing PMD tables When huge_pmd_unshare() is called to unshare a PMD table, the tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables in th...

Affected product and versions

Product
Linux
Affected versions
>= 6495204f8219a57859669d618b25d06176d5a872 < dced308d7d6a0de1c09d2058f38f1aaaf5cbb914, >= ce4cf24761467756462c0e1dbe4a5e9c9eb520fc < 47490bbb05c8c0e09cc3cfd237d8934ffc340583, >= daa6707b71a2da23a82979fa21f788aeb706f1a2 < 0199c9d57861f17b556b6cba1f765c7cce79745b, >= ff37dd18ce7739a26aab0cc2d31006a45e6bde63 < d766a49d9b55705c4737cd8bb5d3faa2d31330fd, >= da06bb0ca45b1ca6f1ab55023e34e61a520337f3 < 8ca7284da0e67b3e71d90ec17f08286774245ad9, >= 9b671f6f432be07c0ddd66e437d6d0e0db684f83 < fe93e907b1af03cc229a80aa64a570a103d2b279, >= 8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1 < 48125cd9c55cbe297b59fd1f9bda48b0960bd181, >= 8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1 < c2ff4764e03e7a8d758352f4aceb8fe1be6ac971, >= 5.10.253 < 5.10.259, >= 5.15.203 < 5.15.210, >= 6.1.167 < 6.1.176, >= 6.6.127 < 6.6.143, >= 6.12.74 < 6.12.93, >= 6.18.13 < 6.18.35, >= 6.19
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux 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
Not available