CVE-2026-98127Public exploitHinoki check available

File-size limit bypass via unchecked insert range

Published Sep 25, 2026 · Updated Sep 25, 2026

Improper size validation in the Linux SMB client allows local users to create oversized files through CIFS insert-range operations. The smb3_insert_range() path adds len to i_size without checking arithmetic overflow or calling inode_newsize_ok() before changing the file. Exploitation requires local write access to a file on a CIFS mount; the resulting size can bypass RLIMIT_FSIZE, exceed s_maxbytes, or fall outside loff_t.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper size validation in the Linux SMB client allows local users to create oversized files through CIFS insert-range operations. The smb3_insert_range() path adds len to i_size without checking arithmetic overflow or calling inode_newsize_ok() before changing the file. Exploitation requires local write access to a file on a CIFS mount; the resulting size can bypass RLIMIT_FSIZE, exceed s_maxbytes, or fall outside loff_t.

The record

CVE
CVE-2026-98127
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.13
  2. Affected versionversion=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e
  3. Affected versionversion=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <7c2c69045aa76ccaa7f16f1478eb312130ce4951
  4. Affected versionversion=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <bc7602b9082ef195d913c4c16fa9853dd262333e
  5. Affected versionversion=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <f8cbfe3a3fcee7d991fd223f660f3e5df13221cf

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e; version=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <7c2c69045aa76ccaa7f16f1478eb312130ce4951; version=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <bc7602b9082ef195d913c4c16fa9853dd262333e; version=7fe6fe95b936084dce6eedcc2cccadf96eafae73 <f8cbfe3a3fcee7d991fd223f660f3e5df13221cf

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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