CVE-2025-21830Public exploit

Sandbox bypass via unrecognized inode types

Published Mar 6, 2025 · Updated Aug 5, 2026

Improper access control in Linux kernel Landlock allows local users to bypass sandbox write restrictions through crafted filesystem inodes. The get_mode_access() helper in security/landlock/fs.c returns an empty access mask for an unrecognized S_IFMT value, so Landlock permits link or rename operations instead of requiring the regular-file creation right. Exploitation requires a mounted crafted filesystem and a self-created Landlock domain; it enables limited protected-directory changes and can panic hosts configured with panic_on_warn.

CVSS severity7.3
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Linux kernel Landlock allows local users to bypass sandbox write restrictions through crafted filesystem inodes. The get_mode_access() helper in security/landlock/fs.c returns an empty access mask for an unrecognized S_IFMT value, so Landlock permits link or rename operations instead of requiring the regular-file creation right. Exploitation requires a mounted crafted filesystem and a self-created Landlock domain; it enables limited protected-directory changes and can panic hosts configured with panic_on_warn.

The record

CVE
CVE-2025-21830
Published
Mar 6, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 6, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record 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=5.13
  2. Affected versionversion=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <0fde195a373ab1267e60baa9e1a703a97e7464cd
  3. Affected versionversion=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <2569e65d2eb6ac1afe6cb6dfae476afee8b6771a
  4. Affected versionversion=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <39bb3d56f1c351e76bb18895d0e73796e653d5c1
  5. Affected versionversion=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <49440290a0935f428a1e43a5ac8dc275a647ff80
  6. Affected versionversion=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <7d6121228959ddf44a4b9b6a177384ac7854e2f9
  7. Affected versionversion=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <a1fccf6b72b56343dd4f2d96b008147f9951eebd

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <0fde195a373ab1267e60baa9e1a703a97e7464cd; version=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <2569e65d2eb6ac1afe6cb6dfae476afee8b6771a; version=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <39bb3d56f1c351e76bb18895d0e73796e653d5c1; version=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <49440290a0935f428a1e43a5ac8dc275a647ff80; version=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <7d6121228959ddf44a4b9b6a177384ac7854e2f9; version=cb2c7d1a1776057c9a1f48ed1250d85e94d4850d <a1fccf6b72b56343dd4f2d96b008147f9951eebd

Published CVSS scores

5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.3LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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 exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

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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