CVE-2026-64064· NVD / CVE Program· CNA Linux

netfs: Fix netfs_invalidate_folio() to clear dirty bit if all changes gone

Noroxi assessment

Priority: Monitor (action score 22/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 156ac2ec2ee77c44c4eb7439d6d165247ba12247, 31ba145faceb378fa01afcb8349e15ea7d95e542, 65ae8717abf36202fef02260b64b781d2d44a9bf.

Low priority for now. Upgrade to Linux Linux 156ac2ec2ee77c44c4eb7439d6d165247ba12247, 31ba145faceb378fa01afcb8349e15ea7d95e542, 65ae8717abf36202fef02260b64b781d2d44a9bf or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_invalidate_folio() to clear dirty bit if all changes gone If a streaming write is made, this will leave the relevant modified folio in a not-uptodate, but dirty state with a netfs_folio struct hung off of folio->private indicating the dirty range. Subsequently truncating the file such that the dirty data in the folio is removed, but the first part of the folio theoretically remains will cause the netfs_folio struct to be discarded... but will leave the dirty flag set. If the folio is then read via mmap(), netfs_read_folio() will see that the page is dirty and jump to netfs_read_gaps() to fill in the missing bits. netfs_read_gaps(), however, expects there to be a netfs_folio struct present and can oops because truncate removed it. Fix this by calling folio_cancel_dirty() in netfs_invalidate_folio() in the event that all the dirty data in the folio is erased (as nfs does). Also add some tracepoints to log modifications to a dirty page. This can be reproduced with something like: dd if=/dev/zero of=/xfstest.test/foo bs=1M count=1 umount /xfstest.test mount /xfstest.test xfs_io -c "w 0xbbbf 0xf96c" \ -c "truncate 0xbbbf" \ -c "mmap -r 0xb000 0x11000" \ -c "mr 0xb000 0x11000" \ /xfstest.test/foo with fscaching disabled (otherwise streaming writes are suppressed) and a change to netfs_perform_write() to disallow streaming writes if the fd is open O_RDWR: if (//(file->f_mode & FMODE_READ) || <--- comment this out netfs_is_cache_enabled(ctx)) { It should be reproducible even without this change, but if prevents the above trivial xfs_io command from reproducing it. Note that the initial dd is important: the file must start out sufficiently large that the zero-point logic doesn't just clear the gaps because it knows there's nothing in the file to read yet. Unmounting and mounting is needed to clear the pagecache (there are other ways to do that that may also work). This was initially reproduced with the generic/522 xfstest on some patches that remove the FMODE_READ restriction.

MediumCVSS 5.5 · v3.1—No exploit Fix available

Denial of service

Published: Jul 19, 2026
Updated: Sep 3, 2026
EPSS: 0.1% · 1th percentile
CWE: —

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Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

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Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel6.8 and later · before 6.12.92
linux linux kernel6.13 and later · before 6.18.34
linux linux kernel6.19 and later · before 7.0.11
linux linux kernel7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 6.8affected
- 9ebff83e648148b9ece97d4e4890dd84ca54d6ce and later · before 31ba145faceb378fa01afcb8349e15ea7d95e542affected · git
- 9ebff83e648148b9ece97d4e4890dd84ca54d6ce and later · before fb6ec883b48b8789e5e690dcd440d2db941e840caffected · git
- 9ebff83e648148b9ece97d4e4890dd84ca54d6ce and later · before 65ae8717abf36202fef02260b64b781d2d44a9bfaffected · git
- 9ebff83e648148b9ece97d4e4890dd84ca54d6ce and later · before 156ac2ec2ee77c44c4eb7439d6d165247ba12247affected · git
- before 6.8not affected · semver
- 6.12.92 and later · up to and including 6.12.*not affected · semver
- 6.18.34 and later · up to and including 6.18.*not affected · semver
- 7.0.11 and later · up to and including 7.0.*not affected · semver
- 7.1 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:13	linux	before 6.12.94-1	6.12.94-1
Debian:14	linux	before 7.0.12-1	7.0.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now
CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
83Now

Published before and after this one in the same product

← EarlierCVE-2026-64062Jul 19, 2026 · netfs: Fix potential deadlock in write-through mode
22Monitor
← EarlierCVE-2026-64063Jul 19, 2026 · netfs: Fix streaming write being overwritten
31Monitor
Later →CVE-2026-64065Jul 19, 2026 · netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	156ac2ec2ee77c44c4eb7439d6d165247ba12247	Vendor (CNA)
Linux Linux	31ba145faceb378fa01afcb8349e15ea7d95e542	Vendor (CNA)
Linux Linux	65ae8717abf36202fef02260b64b781d2d44a9bf	Vendor (CNA)
Linux Linux	fb6ec883b48b8789e5e690dcd440d2db941e840c	Vendor (CNA)
debian:linux	6.12.94-1 · Debian:13	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/156ac2ec2ee77c44c4eb7439d6d165247ba12247

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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