Medium · CVSS 5.5CVE-2026-64040

cachefiles: Fix error return when vfs_mkdir() failsCVE-2026-64040

Answer in brief

CVE-2026-64040 records a Medium severity (CVSS 5.5) vulnerability in cachefiles: Fix error return when vfs_mkdir() fails. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 19, 2026Updated Oct 15, 2026Source checked Oct 15, 2026First seen by HOL Oct 14, 2026Material review Oct 15, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.5
Exploitation: Not marked as known exploited
Affected software: 7 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc1::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc2::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc3::::::	Not reported	Not reported
cpe:2.3:o:linux:linux_kernel:7.1:rc4::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=406fad7698f5bf21ab6b5ca195bf4b9e0b3990ed <86f4c1586418d50203ee8d76cba5d7b148719a32 \|\| >=406fad7698f5bf21ab6b5ca195bf4b9e0b3990ed <0940108d27c6995e02819ff832be11892f0b208b \|\| >=406fad7698f5bf21ab6b5ca195bf4b9e0b3990ed <8a220d1c312c66194f4a33dd52d1fba42bc2b341	86f4c1586418d50203ee8d76cba5d7b148719a32, 0940108d27c6995e02819ff832be11892f0b208b, 8a220d1c312c66194f4a33dd52d1fba42bc2b341
Linux/Linuxgeneric	6.15	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 86f4c1586418d50203ee8d76cba5d7b148719a32 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 14, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix error return when vfs_mkdir() fails When vfs_mkdir() fails, the error code is not extracted from the returned error pointer. This causes mkdir_error to be reached with ret=0, which leads to returning ERR_PTR(0) (NULL) instead of a proper error pointer. Fix this by extracting the error code from the error pointer when vfs_mkdir() fails.

Quoted source text, attributed separately from HOL analysis.