CVE-2025-40259

Local service interruption via atomic-context sleep

Published Dec 4, 2025 · Updated Jun 16, 2026

A concurrency flaw in the Linux kernel SCSI generic driver allows local users to interrupt service through request completion. Within drivers/scsi/sg.c, sg_finish_rem_req() calls the potentially sleeping blk_rq_unmap_user() routine while interrupts are disabled, violating atomic-context constraints. Exploitation requires local low-privileged access and reachability of the SCSI generic request path; the documented consequence is limited to kernel availability.

CVSS severity5.5
Medium
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

A concurrency flaw in the Linux kernel SCSI generic driver allows local users to interrupt service through request completion. Within drivers/scsi/sg.c, sg_finish_rem_req() calls the potentially sleeping blk_rq_unmap_user() routine while interrupts are disabled, violating atomic-context constraints. Exploitation requires local low-privileged access and reachability of the SCSI generic request path; the documented consequence is limited to kernel availability.

The record

CVE
CVE-2025-40259
Published
Dec 4, 2025
Updated
Jun 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 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=3.16.85 <3.17
  2. Affected versionversion=3.18.101 <3.19
  3. Affected versionversion=4.12
  4. Affected versionversion=4.1.52 <4.2
  5. Affected versionversion=4.4.123 <4.5
  6. Affected versionversion=4.9.89 <4.10
  7. Affected versionversion=4a8e8e0af9a520a685e0ab2d489327d5220d7ce2
  8. Affected versionversion=6af37613289cfd32516ada47e444b48a638829c8
  9. Affected versionversion=8d1f3b474a89b42f957ba3bae959dd3cd16531ca
  10. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <109afbd88ecc46b6cc7551367222387e97999765
  11. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <11eeee00c94d770d4e45364060b5f1526dfe567b
  12. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <3dfd520c3b4ffe69e0630c580717d40447ab842f
  13. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <6983d8375c040bb449d2187f4a57a20de01244fe
  14. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <90449f2d1e1f020835cba5417234636937dd657e
  15. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <b2c0340cfa25c5c1f65e8590cc1a2dc97d14ef0f
  16. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <b343cee5df7e750d9033fba33e96fc4399fa88a5
  17. Affected versionversion=97d27b0dd015e980ade63fda111fd1353276e28b <db6ac8703ab2b473e1ec845f57f6dd961a388d9f
  18. Affected versionversion=ae9b6ae2e77947534e255903627cc62746ea77e2
  19. Affected versionversion=fa55ef3f803fc7c20be0ab809e6278c31febd875

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.16.85 <3.17; version=3.18.101 <3.19; version=4.12; version=4.1.52 <4.2; version=4.4.123 <4.5; version=4.9.89 <4.10; version=4a8e8e0af9a520a685e0ab2d489327d5220d7ce2; version=6af37613289cfd32516ada47e444b48a638829c8; version=8d1f3b474a89b42f957ba3bae959dd3cd16531ca; version=97d27b0dd015e980ade63fda111fd1353276e28b <109afbd88ecc46b6cc7551367222387e97999765; version=97d27b0dd015e980ade63fda111fd1353276e28b <11eeee00c94d770d4e45364060b5f1526dfe567b; version=97d27b0dd015e980ade63fda111fd1353276e28b <3dfd520c3b4ffe69e0630c580717d40447ab842f; version=97d27b0dd015e980ade63fda111fd1353276e28b <6983d8375c040bb449d2187f4a57a20de01244fe; version=97d27b0dd015e980ade63fda111fd1353276e28b <90449f2d1e1f020835cba5417234636937dd657e; version=97d27b0dd015e980ade63fda111fd1353276e28b <b2c0340cfa25c5c1f65e8590cc1a2dc97d14ef0f; version=97d27b0dd015e980ade63fda111fd1353276e28b <b343cee5df7e750d9033fba33e96fc4399fa88a5; version=97d27b0dd015e980ade63fda111fd1353276e28b <db6ac8703ab2b473e1ec845f57f6dd961a388d9f; version=ae9b6ae2e77947534e255903627cc62746ea77e2; version=fa55ef3f803fc7c20be0ab809e6278c31febd875

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

T1499.004Application or System Exploitation

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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