CyberSecBulletin
CVE-2026-46115NVD status: Undergoing Analysis

In the Linux kernel, the following vulnerability has been resolved: block: add pgmap check to…

Published Updated By the CyberSecBulletin desk

CVE-2026-46115 is a critical-severity improper input validation vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 3d2ecbd444b01d6500671d1a582b7393943cf539, a7f3aa8c9df3905fe820ae36b67ba56b81587574, f17d521075325b8afc42d1baa1c28a5e9aca111f as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 3d2ecbd444b01d6500671d1a582b7393943cf539 or a7f3aa8c9df3905fe820ae36b67ba56b81587574 or f17d521075325b8afc42d1baa1c28a5e9aca111f or f632dab4b841554cd6416058c61886d7db176581, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.140 or 6.12.88 or 6.18.30 or 7.0.7, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux49580e690755d0e51ed7aa2c33225dd884fa738a up to, but not including, 3d2ecbd444b01d6500671d1a582b7393943cf539; 49580e690755d0e51ed7aa2c33225dd884fa738a up to, but not including, a7f3aa8c9df3905fe820ae36b67ba56b81587574; 49580e690755d0e51ed7aa2c33225dd884fa738a up to, but not including, f17d521075325b8afc42d1baa1c28a5e9aca111f; 49580e690755d0e51ed7aa2c33225dd884fa738a up to, but not including, f632dab4b841554cd6416058c61886d7db176581; 49580e690755d0e51ed7aa2c33225dd884fa738a up to, but not including, 13920e4b7b784b40cf4519ff1f0f3e513476a499; 6.23d2ecbd444b01d6500671d1a582b7393943cf539, a7f3aa8c9df3905fe820ae36b67ba56b81587574, f17d521075325b8afc42d1baa1c28a5e9aca111f, f632dab4b841554cd6416058c61886d7db176581, 13920e4b7b784b40cf4519ff1f0f3e513476a499
LinuxLinux Kernel6.2 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.76.6.140, 6.12.88, 6.18.30, 7.0.7

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Input Validation vulnerabilities

Spotted an error? Tell us.