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NVD / CVE Program· CNA Linux

CVE-2026-93794: smb/client: flush dirty data before punching a hole

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: 0.16% (FIRST EPSS).
  • Fixed version: Linux Linux 0c9fcab9bf1ef3516983f3de05a19c5658c7a01e, 216e469586057c29409e4ef8311d282388c6e251, 39562a56cdb515f6635c3e7bfe6629439b18a169; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.

Low priority for now. Upgrade to Linux Linux 0c9fcab9bf1ef3516983f3de05a19c5658c7a01e, 216e469586057c29409e4ef8311d282388c6e251, 39562a56cdb515f6635c3e7bfe6629439b18a169; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 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: flush dirty data before punching a hole Punching a hole after a large buffered write may leave the range reported as data. Reproduce it with: xfs_io -f \ -c "pwrite -b 3m -S 0x61 0 3m" \ -c "fpunch 1m 1m" \ -c "seek -h 0" \ -c "seek -d 1m" \ /mnt/test/repro Punching 1 MiB at offset 1 MiB should produce: 0 1 MiB 2 MiB 3 MiB | DATA | HOLE | DATA | EOF Instead, the entire file is reported as data. SEEK_HOLE(0) returns EOF, and SEEK_DATA(1M) returns 1M. This happens because a dirty folio spanning the punched range can be written back after the punch and refill the hole. Fix this by flushing and waiting for dirty data in the punched range before invalidating the page cache and issuing FSCTL_SET_ZERO_DATA. The xfstests generic/539 pass against Samba/ksmbd with this change.

—No exploit Fix available
Published
Sep 24, 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%

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  • Not in KEV: no record of exploitation in the wild
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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

    • 3.17affected
    • 31742c5a331766bc7df6b0d525df00c6cd20d5a6 and later · before 0c9fcab9bf1ef3516983f3de05a19c5658c7a01eaffected · git
    • 31742c5a331766bc7df6b0d525df00c6cd20d5a6 and later · before 216e469586057c29409e4ef8311d282388c6e251affected · git
    • 31742c5a331766bc7df6b0d525df00c6cd20d5a6 and later · before 6c265aca08155e519a8f6f6071c59dff4f535f70affected · git
    • 31742c5a331766bc7df6b0d525df00c6cd20d5a6 and later · before 39562a56cdb515f6635c3e7bfe6629439b18a169affected · git
    • 31742c5a331766bc7df6b0d525df00c6cd20d5a6 and later · before d7d2adcd022baade5cab65ca492ce63421ce3a6eaffected · git
    • before 3.17not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.158 and later · up to and including 6.6.*not affected · semver
    • 6.12.111 and later · up to and including 6.12.*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 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

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-2026-93792Sep 24, 2026 · wifi: iwlwifi: mvm: fix a possible underflow
    0Monitor
  • ← EarlierCVE-2026-93793Sep 24, 2026 · wifi: iwlwifi: mvm: validate TX_CMD response layout
    35Monitor
  • Later →CVE-2026-93795Sep 24, 2026 · blk-cgroup: fix leaks and online flag on radix_tree_insert failure
    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 Linux0c9fcab9bf1ef3516983f3de05a19c5658c7a01eVendor (CNA)
Linux Linux216e469586057c29409e4ef8311d282388c6e251Vendor (CNA)
Linux Linux39562a56cdb515f6635c3e7bfe6629439b18a169Vendor (CNA)
Linux Linux6c265aca08155e519a8f6f6071c59dff4f535f70Vendor (CNA)
Linux Linuxd7d2adcd022baade5cab65ca492ce63421ce3a6eVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~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.

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

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. Fix✗ → ✓

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References

Show all references (4 more)

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

All records