PT-2026-61498 · Linux · Linux Kernel

CVE-2026-64181 · Published 2026-07-19 · Updated 2026-07-19

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the memory management subsystem where the vm normal page() function fails to properly handle missing support for pmd special() and pud special(). On x86 32-bit systems with Transparent Huge Pages (THP) enabled, this can lead to incorrect state tracking for huge zero folios, causing them to be miscounted as file-backed THP in smaps, pagemap, and numamaps. This flaw can trigger kernel warnings and bugs related to bad rss-counter and page states during memory reclaim processes via the shrink huge zero folio scan() function. The root cause is that pmd special() and pmd mkspecial() rely on CONFIG ARCH SUPPORTS PMD PFNMAP, which is not enabled on any 32-bit architecture.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-64181

Affected Products

Linux Kernel

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2026-64181 · Security Note
• https://git.kernel.org/stable/c/62153767e8fc3889bc6508e9ffe927aaf64c4334 · Note
• https://git.kernel.org/stable/c/c0c6ccd9828c3a1950623b546fa57292a77b5c73 · Note
• https://twitter.com/CVEnew/status/2078951949353832864 · Twitter Post
• https://git.kernel.org/stable/c/9052ea2ee2233be5d4786b8909151ca2bfbedf99 · Note
• https://twitter.com/infoflowcloud/status/2078953250603122884 · Twitter Post