CVE-2025-38549

Service interruption via leaked mount contexts

Published Aug 16, 2025 · Updated May 11, 2026

Memory leak in the efivarfs filesystem in Linux allows local users to interrupt service through failed mount contexts. efivarfs allocates efivarfs_fs_info during fs_context initialization but does not free it when the context is torn down before fill_super transfers ownership to the superblock. Triggering the leak requires local mount operations and CAP_SYS_ADMIN; repeated failures can exhaust kernel memory without affecting confidentiality or integrity.

CVSS severity5.5
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the efivarfs filesystem in Linux allows local users to interrupt service through failed mount contexts. efivarfs allocates efivarfs_fs_info during fs_context initialization but does not free it when the context is torn down before fill_super transfers ownership to the superblock. Triggering the leak requires local mount operations and CAP_SYS_ADMIN; repeated failures can exhaust kernel memory without affecting confidentiality or integrity.

The record

CVE
CVE-2025-38549
Published
Aug 16, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 16, 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=5329aa5101f73c451bcd48deaf3f296685849d9c <64e135f1eaba0bbb0cdee859af3328c68d5b9789
  2. Affected versionversion=5329aa5101f73c451bcd48deaf3f296685849d9c <816d36973467d1c9c08a48bdffe4675e219a2e84
  3. Affected versionversion=5329aa5101f73c451bcd48deaf3f296685849d9c <e9fabe7036bb8be6071f39dc38605508f5f57b20
  4. Affected versionversion=6.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5329aa5101f73c451bcd48deaf3f296685849d9c <64e135f1eaba0bbb0cdee859af3328c68d5b9789; version=5329aa5101f73c451bcd48deaf3f296685849d9c <816d36973467d1c9c08a48bdffe4675e219a2e84; version=5329aa5101f73c451bcd48deaf3f296685849d9c <e9fabe7036bb8be6071f39dc38605508f5f57b20; version=6.7

Published CVSS scores

5.5NVDCVSS: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 exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.001Endpoint Denial of Service: OS Exhaustion Flood

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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