CVE-2025-38698Public exploit

Kernel crash via unchecked negative file size

Published Sep 4, 2025 · Updated May 12, 2026

Improper input validation in Linux JFS allows local users to crash the kernel by opening a corrupted regular file. The open path in fs/jfs/file.c accepts a negative on-disk inode size, allowing later writes to reach an assertion in jfs_truncate_nolock. Exploitation requires local access to supply and open a crafted JFS image; the demonstrated consequence is a kernel crash, not reported code execution.

CVSS severity5.5
Medium
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 input validation in Linux JFS allows local users to crash the kernel by opening a corrupted regular file. The open path in fs/jfs/file.c accepts a negative on-disk inode size, allowing later writes to reach an assertion in jfs_truncate_nolock. Exploitation requires local access to supply and open a crafted JFS image; the demonstrated consequence is a kernel crash, not reported code execution.

The record

CVE
CVE-2025-38698
Published
Sep 4, 2025
Updated
May 12, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-20, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 4, 2025CVE publishedPublication date reported by the CVE source.
  2. May 12, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <00462be586b33076f8b8023e7ba697deedc131db
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <02edcfda419168d9405bffe55f18ea9c1bf92366
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2d04df8116426b6c7b9f8b9b371250f666a2a2fb
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6bc86f1d7d5419d5b19483ba203ca0b760c41c51
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <78989af5bbf55a0cf1165b0fa73921bc02f1543b
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9605cb2ea38ba014d0e704cba0dbbb00593fa9fd
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9ad054cd2c4ca8c371e555748832aa217c41fc65
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9f896c3d0192241d6438be6963682ace8203f502
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd9454b7710b28060faa49b041f8283c435721a3
  10. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <00462be586b33076f8b8023e7ba697deedc131db; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <02edcfda419168d9405bffe55f18ea9c1bf92366; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2d04df8116426b6c7b9f8b9b371250f666a2a2fb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6bc86f1d7d5419d5b19483ba203ca0b760c41c51; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <78989af5bbf55a0cf1165b0fa73921bc02f1543b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9605cb2ea38ba014d0e704cba0dbbb00593fa9fd; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9ad054cd2c4ca8c371e555748832aa217c41fc65; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9f896c3d0192241d6438be6963682ace8203f502; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd9454b7710b28060faa49b041f8283c435721a3; version=2.6.12
Siemens · SIMATIC CN 4100version=0 <V5.0

Published CVSS scores

7.0Siemens ProductCERTCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5NIST NVDCVSS: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 exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
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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