CVE-2025-68806Network attack vector

Kernel heap disclosure via omitted EA terminator

Published Jan 13, 2026 · Updated Jan 13, 2026

Information disclosure in Linux Kernel ksmbd allows remote attackers to read kernel heap data through malformed SMB2 extended attributes. The smb2_set_ea handler omits the one-byte EA-name terminator from its length check, so a crafted SET_INFO request stores an uninitialized receive-buffer byte in a user xattr. Exposure requires a running ksmbd server and FILE_WRITE_EA access, which passwordless guests can hold on guest-writable shares; repeated queries disclose kernel heap contents without a crash or write primitive.

CVSS severity7.5
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Linux Kernel ksmbd allows remote attackers to read kernel heap data through malformed SMB2 extended attributes. The smb2_set_ea handler omits the one-byte EA-name terminator from its length check, so a crafted SET_INFO request stores an uninitialized receive-buffer byte in a user xattr. Exposure requires a running ksmbd server and FILE_WRITE_EA access, which passwordless guests can hold on guest-writable shares; repeated queries disclose kernel heap contents without a crash or write primitive.

The record

CVE
CVE-2025-68806
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 13, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6dc8cf6e7998ef7aeb9383a4c2904ea5d22fa2e4
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <95d7a890e4b03e198836d49d699408fd1867cb55
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a28a375a5439eb474e9f284509a407efb479c925
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cae52c592a07e1d3fa3338a5f064a374a5f26750
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d26af6d14da43ab92d07bc60437c62901dc522e6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6dc8cf6e7998ef7aeb9383a4c2904ea5d22fa2e4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <95d7a890e4b03e198836d49d699408fd1867cb55; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a28a375a5439eb474e9f284509a407efb479c925; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cae52c592a07e1d3fa3338a5f064a374a5f26750; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d26af6d14da43ab92d07bc60437c62901dc522e6

Published CVSS scores

7.5Linux Kernel CVE TeamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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