CVE-2026-99115Network attack vector

Information disclosure via uninitialized filesystem identifier

Published Oct 28, 2026 · Updated Oct 28, 2026

Information disclosure in Linux ksmbd allows remote authenticated users to read stale bytes via compound SMB requests. The smb2_get_info_filesystem() handler returns FS_POSIX_INFORMATION without assigning its eight-byte FileSysIdentifier field, exposing bytes left by an earlier response replaced with a shorter error. Exposure requires a running ksmbd server, an accessible share, a valid SMB session, and negotiated POSIX extensions; standalone requests return zeroed bytes rather than leaking data.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Linux ksmbd allows remote authenticated users to read stale bytes via compound SMB requests. The smb2_get_info_filesystem() handler returns FS_POSIX_INFORMATION without assigning its eight-byte FileSysIdentifier field, exposing bytes left by an earlier response replaced with a shorter error. Exposure requires a running ksmbd server, an accessible share, a valid SMB session, and negotiated POSIX extensions; standalone requests return zeroed bytes rather than leaking data.

The record

CVE
CVE-2026-99115
Published
Oct 28, 2026
Updated
Oct 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 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=5.15
  2. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <ab057f271ef60ff8163818badc3de75c480eca07
  3. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <beba2ef6f66a71f20531ac70a1acb0b221e362e9
  4. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <db2267b27c054a6c2151ff7fbb67927e784f31d6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <ab057f271ef60ff8163818badc3de75c480eca07; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <beba2ef6f66a71f20531ac70a1acb0b221e362e9; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <db2267b27c054a6c2151ff7fbb67927e784f31d6

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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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