🛡️ CVE-2026-43303 — kernel

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

mm/page_alloc: clear page->private in free_pages_prepare()

In the Linux kernel, the following vulnerability has been resolved:

mm/page_alloc: clear page->private in free_pages_prepare()

Several subsystems (slub, shmem, ttm, etc.) use page->private but don't

clear it before freeing pages. When these pages are later allocated as

high-order pages and split via split_page(), tail pages retain stale

page->private values.

This causes a use-after-free in the swap subsystem. The swap code uses

page->private to track swap count continuations, assuming freshly

allocated pages have page->private == 0. When stale values are present,

swap_count_continued() incorrectly assumes the continuation list is valid

and iterates over uninitialized page->lru containing LIST_POISON values,

causing a crash:

KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]

RIP: 0010:__do_sys_swapoff+0x1151/0x1860

Fix this by clearing page->private in free_pages_prepare(), ensuring all

freed pages have clean state regardless of previous use.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Affected software

CVE-2026-43303 is recorded against 3 packages.

  • kernel (from 6.19.0 up to 6.19.6)
  • linux-kernel
  • unknown

Timeline and source

Published on 8 May 2026 and last revised on 6 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

CVE-2026-43303 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2026-05-08
Updated 2026-08-12
Modified 2026-08-06

Affected Packages

Software From version Fixed in
kernel 6.19.0 6.19.6
linux-kernel — —
unknown — —

Similar Threats

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