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NVD / CVE Program· CNA Linux

CVE-2026-31438: netfs: Fix kernel BUG in netfs_limit_iter() for ITER_KVEC iterators

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 00d6df7115f6972370974212de9088087820802e, 18c2e20b42dd21db599e42d05ddaeeb647b2bb6d, 4bc2d72c7695cedf6d4e1a558924903c2b28a78e.

Low priority for now. Upgrade to Linux Linux 00d6df7115f6972370974212de9088087820802e, 18c2e20b42dd21db599e42d05ddaeeb647b2bb6d, 4bc2d72c7695cedf6d4e1a558924903c2b28a78e 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 kernel BUG in netfs_limit_iter() for ITER_KVEC iterators When a process crashes and the kernel writes a core dump to a 9P filesystem, __kernel_write() creates an ITER_KVEC iterator. This iterator reaches netfs_limit_iter() via netfs_unbuffered_write(), which only handles ITER_FOLIOQ, ITER_BVEC and ITER_XARRAY iterator types, hitting the BUG() for any other type. Fix this by adding netfs_limit_kvec() following the same pattern as netfs_limit_bvec(), since both kvec and bvec are simple segment arrays with pointer and length fields. Dispatch it from netfs_limit_iter() when the iterator type is ITER_KVEC.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 22, 2026
Updated
Nov 5, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

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

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-31438

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux 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 6.12.80
  • linux linux kernel6.13 and later · before 6.18.21
  • linux linux kernel6.19 and later · before 6.19.11
  • linux linux kernel7.0

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
    • cae932d3aee55035a54415dcea8e7ecf2ec469b5 and later · before 18c2e20b42dd21db599e42d05ddaeeb647b2bb6daffected · git
    • cae932d3aee55035a54415dcea8e7ecf2ec469b5 and later · before 4bc2d72c7695cedf6d4e1a558924903c2b28a78eaffected · git
    • cae932d3aee55035a54415dcea8e7ecf2ec469b5 and later · before 00d6df7115f6972370974212de9088087820802eaffected · git
    • cae932d3aee55035a54415dcea8e7ecf2ec469b5 and later · before 67e467a11f62ff64ad219dc6aa5459e132c79d14affected · git
    • before 6.8not affected · semver
    • 6.12.80 and later · up to and including 6.12.*not affected · semver
    • 6.18.21 and later · up to and including 6.18.*not affected · semver
    • 6.19.11 and later · up to and including 6.19.*not affected · semver
    • 7.0 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.11-16.19.11-1
openSUSE:Leap 16.0dtb-aarch64before 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-64kbbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-azurebefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-defaultbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-default-basebefore 6.12.0-160000.36.1.160000.2.176.12.0-160000.36.1.160000.2.17
openSUSE:Leap 16.0kernel-docsbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-kvmsmallbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-obs-buildbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-obs-qabefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-rtbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-sourcebefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-symsbefore 6.12.0-160000.36.16.12.0-160000.36.1
openSUSE:Leap 16.0kernel-zfcpdumpbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Enterprise Server 16.0kernel-azurebefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Enterprise Server 16.0kernel-docsbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Enterprise Server 16.0kernel-kvmsmallbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Enterprise Server 16.0kernel-obs-qabefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Enterprise Server 16.0kernel-zfcpdumpbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Micro 6.2kernel-64kbbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Micro 6.2kernel-defaultbefore 6.12.0-160000.36.16.12.0-160000.36.1
SUSE:Linux Micro 6.2kernel-default-basebefore 6.12.0-160000.36.1.160000.2.176.12.0-160000.36.1.160000.2.17
SUSE:Linux Micro 6.2kernel-rtbefore 6.12.0-160000.36.16.12.0-160000.36.1

+3

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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

Published before and after this one in the same product

  • ← EarlierCVE-2026-31435Apr 22, 2026 · netfs: Fix read abandonment during retry
    35Monitor
  • ← EarlierCVE-2026-31436Apr 22, 2026 · dmaengine: idxd: fix possible wrong descriptor completion in llist_abort_desc()
    39Monitor
  • Later →CVE-2026-31440Apr 22, 2026 · dmaengine: idxd: Fix leaking event log memory
    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 / packageFixed versionSource
Linux Linux00d6df7115f6972370974212de9088087820802eVendor (CNA)
Linux Linux18c2e20b42dd21db599e42d05ddaeeb647b2bb6dVendor (CNA)
Linux Linux4bc2d72c7695cedf6d4e1a558924903c2b28a78eVendor (CNA)
Linux Linux67e467a11f62ff64ad219dc6aa5459e132c79d14Vendor (CNA)
debian:linux6.12.85-1 · Debian:13Package registry (OSV)
opensuse:dtb-aarch646.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-64kb6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-azure6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-default-base6.12.0-160000.36.1.160000.2.17 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-docs6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-kvmsmall6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-build6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-obs-qa6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-rt6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-source6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:kernel-syms6.12.0-160000.36.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:kernel-64kb6.12.0-160000.36.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-azure6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-default6.12.0-160000.36.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-default-base6.12.0-160000.36.1.160000.2.17 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-docs6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-kvmsmall6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-obs-build6.12.0-160000.36.1 · SUSE:Linux Micro Extras 6.2Package registry (OSV)
suse:kernel-obs-qa6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:kernel-rt6.12.0-160000.36.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-source6.12.0-160000.36.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-syms6.12.0-160000.36.1 · SUSE:Linux Micro Extras 6.2Package registry (OSV)
suse:kernel-zfcpdump6.12.0-160000.36.1 · SUSE:Linux Enterprise Server 16.0Package 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.

No history yet (it accumulates with the daily EPSS job).

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)

CWE-476 · NULL Pointer Dereference

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

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (3 more)

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

All records