CVE-2025-39883

Kernel panic via uninitialized page poison check

Published Sep 23, 2025 · Updated Sep 23, 2025

A denial of service in Linux kernel memory-failure handling allows local users to panic the kernel through the hwpoison debugfs interface. The unpoison_memory() function checks the PG_HWPoison flag on an uninitialized page when pfn_to_online_page() returns NULL for an offline page frame. Reachability requires permission to offline memory and write that frame number to unpoison-pfn; the demonstrated consequence is a fatal kernel panic.

CVSS severity7.1
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A denial of service in Linux kernel memory-failure handling allows local users to panic the kernel through the hwpoison debugfs interface. The unpoison_memory() function checks the PG_HWPoison flag on an uninitialized page when pfn_to_online_page() returns NULL for an offline page frame. Reachability requires permission to offline memory and write that frame number to unpoison-pfn; the demonstrated consequence is a fatal kernel panic.

The record

CVE
CVE-2025-39883
Published
Sep 23, 2025
Updated
Sep 23, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 23, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.13
  2. Affected versionversion=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <3d278e89c2ea62b1aaa4b0d8a9766a35b3a3164a
  3. Affected versionversion=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <63a327a2375a8ce7a47dec5aaa4d8a9ae0a00b96
  4. Affected versionversion=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <7618fd443aa4cfa553a64cacf5721581653ee7b0
  5. Affected versionversion=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <d613f53c83ec47089c4e25859d5e8e0359f6f8da
  6. Affected versionversion=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <e4ec6def5643a1c9511115b3884eb879572294c6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.13; version=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <3d278e89c2ea62b1aaa4b0d8a9766a35b3a3164a; version=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <63a327a2375a8ce7a47dec5aaa4d8a9ae0a00b96; version=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <7618fd443aa4cfa553a64cacf5721581653ee7b0; version=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <d613f53c83ec47089c4e25859d5e8e0359f6f8da; version=f1dd2cd13c4bbbc9a7c4617b3b034fa643de98fe <e4ec6def5643a1c9511115b3884eb879572294c6

Published CVSS scores

7.1CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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