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7.8
HIGH CVSS 3.1
CVE-2026-63954
hpfs: fix a crash if hpfs_map_dnode_bitmap fails
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: hpfs: fix a crash if hpfs_map_dnode_bitmap fails If hpfs_map_dnode_bitmap fails, the code would call hpfs_brelse4 on uninitialized quad buffer head, causing a crash.

Details
INFO

Published Date :

July 19, 2026, 4:17 p.m.

Last Modified :

July 27, 2026, 5:44 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-63954 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Update the Linux kernel to resolve a crash caused by uninitialized buffer head usage.
  • Update the Linux kernel to the latest version.
  • Apply relevant patches for the hpfs module.
  • Recompile the kernel if necessary.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-63954.

URL Resource
https://git.kernel.org/stable/c/010b08084000ef018f1a8de5197087f3b91d8cfe
https://git.kernel.org/stable/c/0886c6f257fe3663f80218aa1919b0f3f21bf22c
https://git.kernel.org/stable/c/1648a3c7f4e18f46a4881920133fc4f2494185a0
https://git.kernel.org/stable/c/1d73a533760bc5abb83b3cc759133596f7bb708f
https://git.kernel.org/stable/c/4f37bb30b57d6d403d02673074555bd3c3602bef
https://git.kernel.org/stable/c/7c58c55a2a16f7274772507bd1637be609351b4f
https://git.kernel.org/stable/c/974820a59efde7c1a7e1260bcfe9bb81f833cc9f
https://git.kernel.org/stable/c/d98d8562b3284b5a5c8eb67e71b794508e46e288
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-63954 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-63954 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-63954 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-63954 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 20, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 20, 2026

    Action Type Old Value New Value
    Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '010b08084000ef018f1a8de5197087f3b91d8cfe', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': 'd98d8562b3284b5a5c8eb67e71b794508e46e288', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '1648a3c7f4e18f46a4881920133fc4f2494185a0', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '7c58c55a2a16f7274772507bd1637be609351b4f', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '1d73a533760bc5abb83b3cc759133596f7bb708f', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '0886c6f257fe3663f80218aa1919b0f3f21bf22c', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '4f37bb30b57d6d403d02673074555bd3c3602bef', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '974820a59efde7c1a7e1260bcfe9bb81f833cc9f', 'versionType': 'git'}, {'status': 'affected', 'version': '0', 'lessThan': '5.10.259', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '5.15.210', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.1.176', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.6.143', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.12.93', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.18.35', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '7.0.12', 'versionType': 'semver'}], 'programFiles': ['fs/hpfs/alloc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/hpfs/alloc.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '010b08084000ef018f1a8de5197087f3b91d8cfe', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': 'd98d8562b3284b5a5c8eb67e71b794508e46e288', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '1648a3c7f4e18f46a4881920133fc4f2494185a0', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '7c58c55a2a16f7274772507bd1637be609351b4f', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '1d73a533760bc5abb83b3cc759133596f7bb708f', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '0886c6f257fe3663f80218aa1919b0f3f21bf22c', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '4f37bb30b57d6d403d02673074555bd3c3602bef', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '974820a59efde7c1a7e1260bcfe9bb81f833cc9f', 'versionType': 'git'}], 'programFiles': ['fs/hpfs/alloc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2.6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '2.6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/hpfs/alloc.c'], 'defaultStatus': 'affected'}]
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 19, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '010b08084000ef018f1a8de5197087f3b91d8cfe', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': 'd98d8562b3284b5a5c8eb67e71b794508e46e288', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '1648a3c7f4e18f46a4881920133fc4f2494185a0', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '7c58c55a2a16f7274772507bd1637be609351b4f', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '1d73a533760bc5abb83b3cc759133596f7bb708f', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '0886c6f257fe3663f80218aa1919b0f3f21bf22c', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '4f37bb30b57d6d403d02673074555bd3c3602bef', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '974820a59efde7c1a7e1260bcfe9bb81f833cc9f', 'versionType': 'git'}, {'status': 'affected', 'version': '0', 'lessThan': '5.10.259', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '5.15.210', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.1.176', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.6.143', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.12.93', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '6.18.35', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '7.0.12', 'versionType': 'semver'}], 'programFiles': ['fs/hpfs/alloc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/hpfs/alloc.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: hpfs: fix a crash if hpfs_map_dnode_bitmap fails If hpfs_map_dnode_bitmap fails, the code would call hpfs_brelse4 on uninitialized quad buffer head, causing a crash.
    Added Reference https://git.kernel.org/stable/c/010b08084000ef018f1a8de5197087f3b91d8cfe
    Added Reference https://git.kernel.org/stable/c/0886c6f257fe3663f80218aa1919b0f3f21bf22c
    Added Reference https://git.kernel.org/stable/c/1648a3c7f4e18f46a4881920133fc4f2494185a0
    Added Reference https://git.kernel.org/stable/c/1d73a533760bc5abb83b3cc759133596f7bb708f
    Added Reference https://git.kernel.org/stable/c/4f37bb30b57d6d403d02673074555bd3c3602bef
    Added Reference https://git.kernel.org/stable/c/7c58c55a2a16f7274772507bd1637be609351b4f
    Added Reference https://git.kernel.org/stable/c/974820a59efde7c1a7e1260bcfe9bb81f833cc9f
    Added Reference https://git.kernel.org/stable/c/d98d8562b3284b5a5c8eb67e71b794508e46e288
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact