CVE-2025-40027

Local privilege escalation via 9p request race

Published Oct 28, 2025 · Updated Oct 28, 2025

Memory corruption in the Linux 9p filesystem client allows local users to crash the kernel or gain elevated privileges through 9p I/O. Concurrent cleanup in p9_read_work and p9_fd_cancelled removes the same request twice, prematurely frees its buffers, and later uses corrupted list state. Exploitation requires access to a pre-existing 9p mount and a locally delivered signal, while the resulting kernel corruption permits disclosure, writes, or a panic.

CVSS severity7.8
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

Memory corruption in the Linux 9p filesystem client allows local users to crash the kernel or gain elevated privileges through 9p I/O. Concurrent cleanup in p9_read_work and p9_fd_cancelled removes the same request twice, prematurely frees its buffers, and later uses corrupted list state. Exploitation requires access to a pre-existing 9p mount and a locally delivered signal, while the resulting kernel corruption permits disclosure, writes, or a panic.

The record

CVE
CVE-2025-40027
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-1341, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=3.15
  2. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <0e0097005abc02c9f262370674f855625f4f3fb4
  3. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <284e67a93b8c48952b6fc82129a8d3eb9dc73b06
  4. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <448db01a48e1cdbbc31c995716a5dac1e52ba036
  5. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <674b56aa57f9379854cb6798c3bbcef7e7b51ab7
  6. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <716dceb19a9f8ff6c9d3aee5a771a93d6a47a0b6
  7. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <94797b84cb9985022eb9cb3275c9497fbc883bb6
  8. Affected versionversion=afd8d65411551839b7ab14a539d00075b2793451 <c1db864270eb7fea94a9ef201da0c9dc1cbab7b8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.15; version=afd8d65411551839b7ab14a539d00075b2793451 <0e0097005abc02c9f262370674f855625f4f3fb4; version=afd8d65411551839b7ab14a539d00075b2793451 <284e67a93b8c48952b6fc82129a8d3eb9dc73b06; version=afd8d65411551839b7ab14a539d00075b2793451 <448db01a48e1cdbbc31c995716a5dac1e52ba036; version=afd8d65411551839b7ab14a539d00075b2793451 <674b56aa57f9379854cb6798c3bbcef7e7b51ab7; version=afd8d65411551839b7ab14a539d00075b2793451 <716dceb19a9f8ff6c9d3aee5a771a93d6a47a0b6; version=afd8d65411551839b7ab14a539d00075b2793451 <94797b84cb9985022eb9cb3275c9497fbc883bb6; version=afd8d65411551839b7ab14a539d00075b2793451 <c1db864270eb7fea94a9ef201da0c9dc1cbab7b8

Published CVSS scores

7.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Red HatCVSS: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.

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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-1341Multiple Releases of Same Resource or Handle
T1068Exploitation for Privilege Escalation

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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