CVE-2025-40305

9p request hang via missed receive scheduling

Published Dec 8, 2025 · Updated May 11, 2026

Denial of service in Linux kernel 6.14 through 6.17.7 allows local users to hang 9p file operations by filling a transport pipe. p9_fd_request() checks only EPOLLOUT, so a full pipe can leave EPOLLIN unprocessed and prevent p9_poll_mux() from scheduling receive work. A local process must exercise the 9p file-descriptor transport and fill its pipe; affected operations can remain stalled, interrupting 9p filesystem access.

CVSS severity7.0
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel 6.14 through 6.17.7 allows local users to hang 9p file operations by filling a transport pipe. p9_fd_request() checks only EPOLLOUT, so a full pipe can leave EPOLLIN unprocessed and prevent p9_poll_mux() from scheduling receive work. A local process must exercise the 9p file-descriptor transport and fill its pipe; affected operations can remain stalled, interrupting 9p filesystem access.

The record

CVE
CVE-2025-40305
Published
Dec 8, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 8, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=6.14
  2. Affected versionversion=aaec5a95d59615523db03dd53c2052f0a87beea7 <242531004d7de8c159f9bfadebe33fe8060b1046
  3. Affected versionversion=aaec5a95d59615523db03dd53c2052f0a87beea7 <e8fe3f07a357c39d429e02ca34f740692d88967a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.14; version=aaec5a95d59615523db03dd53c2052f0a87beea7 <242531004d7de8c159f9bfadebe33fe8060b1046; version=aaec5a95d59615523db03dd53c2052f0a87beea7 <e8fe3f07a357c39d429e02ca34f740692d88967a

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0Oracle LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

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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