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Review reviewCritical

CVE-2026-63808

Linux

In the Linux kernel, the following vulnerability has been resolved: exfat: fix potential use-after-free in exfat_find_dir_entry() In exfat_find_dir_entry(), the buffer_head obtained from exfat_get_dentry() is released with brelse(bh) before the fall-through TYPE_EXTEND branch reads the directory entry through ep (which points into bh->b_data): brelse(bh); if (entry_type == TYPE_EXTEND) { ... len = exfat_extract_uni_name(ep, entry_uniname); ... } After brelse() drops our reference, nothing guarantees that the underlying page backing bh->b_data remains valid for the subsequent exfat_extract_u...

CVSS
9.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.19
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: exfat: fix potential use-after-free in exfat_find_dir_entry() In exfat_find_dir_entry(), the buffer_head obtained from exfat_get_dentry() is released with brelse(bh) before the fall-through TYPE_EXTEND branch reads the directory entry through ep (which points into bh->b_data): brelse(bh); if (entry_type == TYPE_EXTEND) { ... len = exfat_extract_uni_name(ep, entry_uniname); ... } After brelse() drops our reference, nothing guarantees that the underlying page backing bh->b_data remains valid for the subsequent exfat_extract_u...

Affected product and versions

Product
Linux
Affected versions
>= ca06197382bde0a3bc20215595d1c9ce20c6e341 < e6f1a11cfb808441a43ffae9b476cc135732cd27, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < e48f413c2815787b8cade2795e194e3c4cd782ef, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < 06c4e1e9967d332ac33ba38b7819851089ff9359, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < 8e0abc17fbd7e305802e84fe98b4950d50f9c433, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < 4d101016d5e587f820b3ae2d5bb6770d86342649, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < adfacfbaeae2cb760f492357cc36b41f84ef7f86, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < 708b97e792945d3e4653939fd3405d71a61ad065, >= ca06197382bde0a3bc20215595d1c9ce20c6e341 < 3f5f8ee9917cc2b9076ac533492d8a200edcabb8, >= 5.7
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. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

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