Review reviewHigh

CVE-2026-63954

Linux

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.

CVSS: 7.8
EPSS: -
CISA KEV: Not listed
Published: 2026.07.20

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 7.8

Vulnerability overview

Affected product and versions

Product: Linux
Affected versions: >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 010b08084000ef018f1a8de5197087f3b91d8cfe, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d98d8562b3284b5a5c8eb67e71b794508e46e288, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1648a3c7f4e18f46a4881920133fc4f2494185a0, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 7c58c55a2a16f7274772507bd1637be609351b4f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1d73a533760bc5abb83b3cc759133596f7bb708f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 0886c6f257fe3663f80218aa1919b0f3f21bf22c, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4f37bb30b57d6d403d02673074555bd3c3602bef, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 974820a59efde7c1a7e1260bcfe9bb81f833cc9f, >= 2.6.12
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linux and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE: Not available