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VulnerabilityPublished Updated

CVE-2026-46115: Linux kernel · block: add pgmap check to biovec_phys_mergeable

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in f632dab4b841554cd6416058c61886d7db176581 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f632dab4b841554cd6416058c61886d7db176581, f17d521075325b8afc42d1baa1c28a5e9aca111f, a7f3aa8c9df3905fe820ae36b67ba56b81587574 +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 49580e690755d0e51ed7aa2c33225dd884fa738a, < f632dab4b841554cd6416058c61886d7db176581
Fixed in
  • f632dab4b841554cd6416058c61886d7db176581
LinuxLinuxAffected
  • ≥ 49580e690755d0e51ed7aa2c33225dd884fa738a, < f17d521075325b8afc42d1baa1c28a5e9aca111f
Fixed in
  • f17d521075325b8afc42d1baa1c28a5e9aca111f
LinuxLinuxAffected
  • ≥ 49580e690755d0e51ed7aa2c33225dd884fa738a, < a7f3aa8c9df3905fe820ae36b67ba56b81587574
Fixed in
  • a7f3aa8c9df3905fe820ae36b67ba56b81587574
LinuxLinuxAffected
  • ≥ 49580e690755d0e51ed7aa2c33225dd884fa738a, < 13920e4b7b784b40cf4519ff1f0f3e513476a499
Fixed in
  • 13920e4b7b784b40cf4519ff1f0f3e513476a499
LinuxLinuxAffected
  • ≥ 49580e690755d0e51ed7aa2c33225dd884fa738a, < 3d2ecbd444b01d6500671d1a582b7393943cf539
Fixed in
  • 3d2ecbd444b01d6500671d1a582b7393943cf539
LinuxLinuxAffected
  • =6.2
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: block: add pgmap check to biovec_phys_mergeable biovec_phys_mergeable() is used by the request merge, DMA mapping, and integrity merge paths to decide if two physically contiguous bvec segments can be coalesced into one. It currently has no check for whether the segments belong to different dev_pagemaps. When zone device memory is registered in multiple chunks, each chunk gets its own dev_pagemap. A single bio can legitimately contain bvecs from different pgmaps -- iov_iter_extract_bvecs() breaks at pgmap boundaries but the outer loop in bio_iov_iter_get_pages() continues filling the same bio. If such bvecs are physically contiguous, biovec_phys_mergeable() will coalesce them, making it impossible to recover the correct pgmap for the merged segment via page_pgmap(). Add a zone_device_pages_have_same_pgmap() check to prevent merging bvec segments that span different pgmaps.

References

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