CVE-2025-40082

Kernel memory disclosure via HFS+ Unicode over-read

Published Oct 28, 2025 · Updated Oct 28, 2025

Out-of-bounds read in the Linux kernel HFS+ filesystem allows local users to disclose kernel memory or crash the system via listxattr(). The hfsplus_listxattr path passes an hfsplus_attr_unistr buffer to hfsplus_uni2asc as the differently sized hfsplus_unistr type, letting its Unicode pointer exceed the allocation when ustrlen is oversized. Exploitation requires low-privileged local access and a mounted HFS+ volume containing a crafted attributes B-tree key; the bounded consequences are memory disclosure and a system crash.

CVSS severity7.1
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

Out-of-bounds read in the Linux kernel HFS+ filesystem allows local users to disclose kernel memory or crash the system via listxattr(). The hfsplus_listxattr path passes an hfsplus_attr_unistr buffer to hfsplus_uni2asc as the differently sized hfsplus_unistr type, letting its Unicode pointer exceed the allocation when ustrlen is oversized. Exploitation requires low-privileged local access and a mounted HFS+ volume containing a crafted attributes B-tree key; the bounded consequences are memory disclosure and a system crash.

The record

CVE
CVE-2025-40082
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record 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=13604b1d7e7b125fb428cddbec6b8d92baad25d5
  2. Affected versionversion=1ca69007e52a73bd8b84b988b61b319816ca8b01
  3. Affected versionversion=291bb5d931c6f3cd7227b913302a17be21cf53b0
  4. Affected versionversion=6.17
  5. Affected versionversion=6f93694bcbc2c2ab3e01cd8fba2f296faf34e6b9
  6. Affected versionversion=73f7da507d787b489761a0fa280716f84fa32b2f
  7. Affected versionversion=76a4c6636a69d69409aa253b049b1be717a539c5
  8. Affected versionversion=94458781aee6045bd3d0ad4b80b02886b9e2219b <857aefc70d4ae3b9bf1ae67434d27d0f79f80c9e
  9. Affected versionversion=94458781aee6045bd3d0ad4b80b02886b9e2219b <bea3e1d4467bcf292c8e54f080353d556d355e26
  10. Affected versionversion=ccf0ad56a779e6704c0b27f555dec847f50c7557
  11. Affected versionversion=f7534cbfac0a9ffa4fa17cacc6e8b6446dae24ee

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=13604b1d7e7b125fb428cddbec6b8d92baad25d5; version=1ca69007e52a73bd8b84b988b61b319816ca8b01; version=291bb5d931c6f3cd7227b913302a17be21cf53b0; version=6.17; version=6f93694bcbc2c2ab3e01cd8fba2f296faf34e6b9; version=73f7da507d787b489761a0fa280716f84fa32b2f; version=76a4c6636a69d69409aa253b049b1be717a539c5; version=94458781aee6045bd3d0ad4b80b02886b9e2219b <857aefc70d4ae3b9bf1ae67434d27d0f79f80c9e; version=94458781aee6045bd3d0ad4b80b02886b9e2219b <bea3e1d4467bcf292c8e54f080353d556d355e26; version=ccf0ad56a779e6704c0b27f555dec847f50c7557; version=f7534cbfac0a9ffa4fa17cacc6e8b6446dae24ee

Published CVSS scores

7.1UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
5.5SUSECVSS: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-125Out-of-bounds Read

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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