CVE-2025-40349

Privilege escalation via unchecked HFS+ record bounds

Published Dec 16, 2025 · Updated Dec 16, 2025

Out-of-bounds access in the Linux HFS+ driver allows local users to escalate privileges by writing to a crafted mounted volume. hfsplus_bmap_alloc trusts the bitmap record offset and length from hfs_brec_lenoff, adds the unchecked offset to node->page, and accesses a page beyond the node allocation. Exploitation requires a crafted HFS+ volume to be mounted and writable; the same access can disclose or corrupt kernel memory or crash the system.

CVSS severity7.8
High
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

Out-of-bounds access in the Linux HFS+ driver allows local users to escalate privileges by writing to a crafted mounted volume. hfsplus_bmap_alloc trusts the bitmap record offset and length from hfs_brec_lenoff, adds the unchecked offset to node->page, and accesses a page beyond the node allocation. Exploitation requires a crafted HFS+ volume to be mounted and writable; the same access can disclose or corrupt kernel memory or crash the system.

The record

CVE
CVE-2025-40349
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0058d20d76182861dbdd8fd6e2dd8d18d6d3becf
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <068a46df3e6acc68fb9db0a6313ab379a11ecd6f
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <17ed51cfce6c62cffb97059ef392ad2e0245806e
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40dfe7a4215a1f20842561ffaf5a6f83a987e75b
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <418e48cab99c52c1760636a4dbe464bf6db2018b
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4f40a2b3969daf10dca4dea6f6dd0e813f79b227
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <738d5a51864ed8d7a68600b8c0c63fe6fe5c4f20
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f7d9f600c7c3ff5dab36181a388af55f2c95604c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0058d20d76182861dbdd8fd6e2dd8d18d6d3becf; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <068a46df3e6acc68fb9db0a6313ab379a11ecd6f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <17ed51cfce6c62cffb97059ef392ad2e0245806e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40dfe7a4215a1f20842561ffaf5a6f83a987e75b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <418e48cab99c52c1760636a4dbe464bf6db2018b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4f40a2b3969daf10dca4dea6f6dd0e813f79b227; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <738d5a51864ed8d7a68600b8c0c63fe6fe5c4f20; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f7d9f600c7c3ff5dab36181a388af55f2c95604c

Published CVSS scores

7.8Linux Kernel CVE TeamCVSS: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 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

T1068Exploitation for Privilege Escalation

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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