CVE-2026-45948

Memory exhaustion via unreleased ext4 extent path

Published May 27, 2026 · Updated May 27, 2026

Memory leak in the ext4 extent-shifting code in affected Linux Kernel releases allows local users to exhaust kernel memory. When ext4_ext_shift_extents() encounters a null extent, it returns without releasing the path allocated by ext4_find_extent(). A local low-privileged user must reach the ext4 extent-shift operation; repeated triggering consumes kernel memory and can interrupt the system without affecting confidentiality or integrity.

CVSS severity5.5
Medium
EPSS probability0.16%
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 ext4 extent-shifting code in affected Linux Kernel releases allows local users to exhaust kernel memory. When ext4_ext_shift_extents() encounters a null extent, it returns without releasing the path allocated by ext4_find_extent(). A local low-privileged user must reach the ext4 extent-shift operation; repeated triggering consumes kernel memory and can interrupt the system without affecting confidentiality or integrity.

The record

CVE
CVE-2026-45948
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=3.15
  2. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <12615ab4bfb69678e5d961b28bb70040299e51b1
  3. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <1bce219ee5512cf179ba40cf114945a14a16e21f
  4. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <2f4b1052246ca646bb17bfe0f53df2fdf9729b58
  5. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <4a79fde8db7eba7f1128d971ceba4e3c9ac84aec
  6. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <7e807cb8603b7664fa630a696cd891d9a03c248d
  7. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <afc5e61e1a07b2b833bd72cbee36ecce9cd901e2
  8. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <bd7b52557e4a3ccd7595fdb3a585f1257de57935
  9. Affected versionversion=a18ed359bdddcded4f97ff5e2f07793ff9336913 <ca81109d4a8f192dc1cbad4a1ee25246363c2833

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.15; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <12615ab4bfb69678e5d961b28bb70040299e51b1; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <1bce219ee5512cf179ba40cf114945a14a16e21f; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <2f4b1052246ca646bb17bfe0f53df2fdf9729b58; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <4a79fde8db7eba7f1128d971ceba4e3c9ac84aec; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <7e807cb8603b7664fa630a696cd891d9a03c248d; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <afc5e61e1a07b2b833bd72cbee36ecce9cd901e2; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <bd7b52557e4a3ccd7595fdb3a585f1257de57935; version=a18ed359bdddcded4f97ff5e2f07793ff9336913 <ca81109d4a8f192dc1cbad4a1ee25246363c2833

Published CVSS scores

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 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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