CVE-2025-37738

Kernel crash via xattrs beyond end marker

Published May 1, 2025 · Updated Aug 5, 2026

Use-after-free in the Linux kernel ext4 xattr cleanup path allows local users to crash the system through crafted extended attributes. The ext4_xattr_inode_dec_ref_all function continues scanning entries beyond the xattr end marker and reads memory that has already been freed. The demonstrated path reaches the fault while unlinking an inode; exploitation requires low-privileged local access and can corrupt kernel memory or crash the system.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel ext4 xattr cleanup path allows local users to crash the system through crafted extended attributes. The ext4_xattr_inode_dec_ref_all function continues scanning entries beyond the xattr end marker and reads memory that has already been freed. The demonstrated path reaches the fault while unlinking an inode; exploitation requires low-privileged local access and can corrupt kernel memory or crash the system.

The record

CVE
CVE-2025-37738
Published
May 1, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 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

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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=4.13
  2. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <362a90cecd36e8a5c415966d0b75b04a0270e4dd
  3. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <3bc6317033f365ce578eb6039445fb66162722fd
  4. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <6aff941cb0f7d0c897c3698ad2e30672709135e3
  5. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <76c365fa7e2a8bb85f0190cdb4b8cdc99b2fdce3
  6. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <836e625b03a666cf93ff5be328c8cb30336db872
  7. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <c8e008b60492cf6fd31ef127aea6d02fd3d314cd
  8. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <cf9291a3449b04688b81e32621e88de8f4314b54
  9. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <eb59cc31b6ea076021d14b04e7faab1636b87d0e
  10. Affected versionversion=e50e5129f384ae282adebfb561189cdb19b81cee <f737418b6de31c962c7192777ee4018906975383

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.13; version=e50e5129f384ae282adebfb561189cdb19b81cee <362a90cecd36e8a5c415966d0b75b04a0270e4dd; version=e50e5129f384ae282adebfb561189cdb19b81cee <3bc6317033f365ce578eb6039445fb66162722fd; version=e50e5129f384ae282adebfb561189cdb19b81cee <6aff941cb0f7d0c897c3698ad2e30672709135e3; version=e50e5129f384ae282adebfb561189cdb19b81cee <76c365fa7e2a8bb85f0190cdb4b8cdc99b2fdce3; version=e50e5129f384ae282adebfb561189cdb19b81cee <836e625b03a666cf93ff5be328c8cb30336db872; version=e50e5129f384ae282adebfb561189cdb19b81cee <c8e008b60492cf6fd31ef127aea6d02fd3d314cd; version=e50e5129f384ae282adebfb561189cdb19b81cee <cf9291a3449b04688b81e32621e88de8f4314b54; version=e50e5129f384ae282adebfb561189cdb19b81cee <eb59cc31b6ea076021d14b04e7faab1636b87d0e; version=e50e5129f384ae282adebfb561189cdb19b81cee <f737418b6de31c962c7192777ee4018906975383

Published CVSS scores

7.1UbuntuCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/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

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499Endpoint Denial of Service

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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