CVE-2025-21907

Kernel warning via missing poisoned-folio unmap flag

Published Apr 1, 2025 · Updated May 23, 2026

Improper exceptional-condition handling in affected Linux kernel releases allows local users to trigger a kernel warning during memory offlining. The unmap_poisoned_folio path fails to apply TTU_HWPOISON when unmapping poisoned anonymous or page-cache folios during migration. Reachability requires a poisoned folio to be migrated during memory offlining; the reported consequence is a warning rather than a crash.

CVSS severity3.3
Low
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exceptional-condition handling in affected Linux kernel releases allows local users to trigger a kernel warning during memory offlining. The unmap_poisoned_folio path fails to apply TTU_HWPOISON when unmapping poisoned anonymous or page-cache folios during migration. Reachability requires a poisoned folio to be migrated during memory offlining; the reported consequence is a warning rather than a crash.

The record

CVE
CVE-2025-21907
Published
Apr 1, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-703
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 1, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 2026Record 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=6.1.16 <6.2
  2. Affected versionversion=6.2.3 <6.3
  3. Affected versionversion=6.3
  4. Affected versionversion=6da6b1d4a7df8c35770186b53ef65d388398e139 <425c12c076e6fc6b2cb04b9f960319d31dcabc76
  5. Affected versionversion=6da6b1d4a7df8c35770186b53ef65d388398e139 <608cc7deb428f1122ed426060233622ebf667b6e
  6. Affected versionversion=6da6b1d4a7df8c35770186b53ef65d388398e139 <b81679b1633aa43c0d973adfa816d78c1ed0d032
  7. Affected versionversion=6dcf132fe236045bd7f50c008660ea086d09af1f
  8. Affected versionversion=deab8114fb67dcb0e6293b665c3c7083fbadff17

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.1.16 <6.2; version=6.2.3 <6.3; version=6.3; version=6da6b1d4a7df8c35770186b53ef65d388398e139 <425c12c076e6fc6b2cb04b9f960319d31dcabc76; version=6da6b1d4a7df8c35770186b53ef65d388398e139 <608cc7deb428f1122ed426060233622ebf667b6e; version=6da6b1d4a7df8c35770186b53ef65d388398e139 <b81679b1633aa43c0d973adfa816d78c1ed0d032; version=6dcf132fe236045bd7f50c008660ea086d09af1f; version=deab8114fb67dcb0e6293b665c3c7083fbadff17

Published CVSS scores

3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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

CWE-703Improper Check or Handling of Exceptional Conditions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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