CVE-2025-40217

Malformed pidfs ioctl acceptance via incomplete command validation

Published Dec 4, 2025 · Updated May 11, 2026

Improper ioctl validation in Linux 6.11 through 6.17.3 allows local users to submit malformed PIDFD_GET_INFO commands to pidfs. pidfs_ioctl_valid() accepted any command sharing the PIDFD_GET_INFO ioctl type, without checking its direction, command number, or minimum structure size. The flaw is reachable through a local pidfd ioctl, while the upstream advisory does not disclose a security consequence beyond accepting invalid request shapes.

CVSS severityUnavailable
Unscored
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

Improper ioctl validation in Linux 6.11 through 6.17.3 allows local users to submit malformed PIDFD_GET_INFO commands to pidfs. pidfs_ioctl_valid() accepted any command sharing the PIDFD_GET_INFO ioctl type, without checking its direction, command number, or minimum structure size. The flaw is reachable through a local pidfd ioctl, while the upstream advisory does not disclose a security consequence beyond accepting invalid request shapes.

The record

CVE
CVE-2025-40217
Published
Dec 4, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 4, 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=5b08bd408534bfb3a7cf5778da5b27d4e4fffe12 <3c17001b21b9f168c957ced9384abe969019b609
  2. Affected versionversion=5b08bd408534bfb3a7cf5778da5b27d4e4fffe12 <bf0fbf5e8b0aff8a4a0fb35e32b10083baa83c04
  3. Affected versionversion=6.11

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5b08bd408534bfb3a7cf5778da5b27d4e4fffe12 <3c17001b21b9f168c957ced9384abe969019b609; version=5b08bd408534bfb3a7cf5778da5b27d4e4fffe12 <bf0fbf5e8b0aff8a4a0fb35e32b10083baa83c04; version=6.11

Published CVSS scores

No CVSS assessment is available in this record.

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

Weakness, pattern, technique

No sourced classifications are available.

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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