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VulnerabilityPublished Updated

CVE-2026-43303: Linux kernel · mm/page_alloc: clear page->private in free_pages_prepare()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% 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 cannot 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 f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b, e7790ab165713b79b1617ce659742ceb3a859d05, d757c793853ec5483eb41ec2942c300b8fa720fb +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 8 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
  • ≥ 3b8000ae185cb068adbda5f966a3835053c85fd4, < f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b
Fixed in
  • f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b
LinuxLinuxAffected
  • ≥ 3b8000ae185cb068adbda5f966a3835053c85fd4, < e7790ab165713b79b1617ce659742ceb3a859d05
Fixed in
  • e7790ab165713b79b1617ce659742ceb3a859d05
LinuxLinuxAffected
  • ≥ 3b8000ae185cb068adbda5f966a3835053c85fd4, < d757c793853ec5483eb41ec2942c300b8fa720fb
Fixed in
  • d757c793853ec5483eb41ec2942c300b8fa720fb
LinuxLinuxAffected
  • ≥ 3b8000ae185cb068adbda5f966a3835053c85fd4, < ac1ea219590c09572ed5992dc233bbf7bb70fef9
Fixed in
  • ac1ea219590c09572ed5992dc233bbf7bb70fef9
LinuxLinuxAffected
  • ≥ 3b8000ae185cb068adbda5f966a3835053c85fd4, < 23b82b7a26182ad840ae67d390d7ec9771e8c00f
Fixed in
  • 23b82b7a26182ad840ae67d390d7ec9771e8c00f
LinuxLinuxAffected
  • ≥ 3b8000ae185cb068adbda5f966a3835053c85fd4, < 3edb8ebbf79b9016040e8f3421d723ae3d542b32
Fixed in
  • 3edb8ebbf79b9016040e8f3421d723ae3d542b32

Description

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.

References

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