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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-98686: smb: client: discard post-EOF pagecache when extending a file via zero range

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 03408d15c5405f8dc3e1a114cdce2174027a85f6, 1ecf89d8efca618e0c758c06b9a1fdde8bd941da, 3df27277f8f95345d4a6c57367824bf1aefdbf66; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1.

Low priority for now. Upgrade to Linux Linux 03408d15c5405f8dc3e1a114cdce2174027a85f6, 1ecf89d8efca618e0c758c06b9a1fdde8bd941da, 3df27277f8f95345d4a6c57367824bf1aefdbf66; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1 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: smb: client: discard post-EOF pagecache when extending a file via zero range smb3_zero_range() removed the pagecache only for the range being zeroed, so when it extends the file the folio straddling the old EOF - which may hold data dirtied past EOF through an mmap - was never dropped and became visible as file content once the file was extended. Lower the discard boundary to the smaller of the zero-range offset and the old EOF.

—No exploit Fix available
Published
Oct 18, 2026
Updated
Oct 30, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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-2026-98686

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.

—

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

    • 5.1affected
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before 1ecf89d8efca618e0c758c06b9a1fdde8bd941daaffected · git
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before 03408d15c5405f8dc3e1a114cdce2174027a85f6affected · git
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before 3df27277f8f95345d4a6c57367824bf1aefdbf66affected · git
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before 94949b6b2f2bf0dba2e8786aed0b08cc6bc3a183affected · git
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before b75dadb50a25eed525264bf6fea44fad94e7626faffected · git
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before 6a8279c98ad289b27c0bdb11adb3f0c0b7fd456daffected · git
    • 72c419d9b073628d3b5b0b2fc787b724f1a8c726 and later · before da4fe97fb6c730d9c94a115c7bfa6f98e0d578d0affected · git
    • before 5.1not affected · semver
    • 5.15.224 and later · up to and including 5.15.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.113-1~deb12u16.12.113-1~deb12u1
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.10-17.2.10-1

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-98684Oct 18, 2026 · smb: client: flush and commit data before querying allocated ranges
    0Monitor
  • ← EarlierCVE-2026-98685Oct 18, 2026 · smb: client: discard post-EOF pagecache when extending a file via clone range
    0Monitor
  • Later →CVE-2026-98687Oct 18, 2026 · thunderbolt: Reject oversized XDomain properties responses
    0Monitor

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 Linux03408d15c5405f8dc3e1a114cdce2174027a85f6Vendor (CNA)
Linux Linux1ecf89d8efca618e0c758c06b9a1fdde8bd941daVendor (CNA)
Linux Linux3df27277f8f95345d4a6c57367824bf1aefdbf66Vendor (CNA)
Linux Linux6a8279c98ad289b27c0bdb11adb3f0c0b7fd456dVendor (CNA)
Linux Linux94949b6b2f2bf0dba2e8786aed0b08cc6bc3a183Vendor (CNA)
Linux Linuxb75dadb50a25eed525264bf6fea44fad94e7626fVendor (CNA)
Linux Linuxda4fe97fb6c730d9c94a115c7bfa6f98e0d578d0Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.06.6.161.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · Debian:12Package 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.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 7, 2026+20 d
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.

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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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. Exploit maturity— → none
  2. Fix✗ → ✓

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

References

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