CVE-2026-68431Network attack vector

Kernel memory disclosure via truncated transform request

Published Aug 12, 2026 · Updated Aug 12, 2026

Out-of-bounds read in Linux ksmbd allows remote attackers to disclose kernel memory via a short SMB2 transform packet. init_smb2_rsp_hdr() treats the undersized transform request as a full 64-byte SMB2 header and copies fields past its allocation into the response. An exposed ksmbd service accepting SMB 2.1 is sufficient; no session authentication or user action is required, and hardened builds can crash.

CVSS severity9.1
Critical
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux ksmbd allows remote attackers to disclose kernel memory via a short SMB2 transform packet. init_smb2_rsp_hdr() treats the undersized transform request as a full 64-byte SMB2 header and copies fields past its allocation into the response. An exposed ksmbd service accepting SMB 2.1 is sufficient; no session authentication or user action is required, and hardened builds can crash.

The record

CVE
CVE-2026-68431
Published
Aug 12, 2026
Updated
Aug 12, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <b62c510f59803f82f9b4c76ead2a56833b2984c7
  2. Affected versionversion=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <cfc0b8e5080aec87700774e8568765eaa4b7b92b
  3. Affected versionversion=5.15.145 <5.16
  4. Affected versionversion=543c12c2644e772caa6880662c2a852cfdc5a10c
  5. Affected versionversion=6.1.34 <6.2
  6. Affected versionversion=6.3.8 <6.4
  7. Affected versionversion=6.4
  8. Affected versionversion=df3a4518aee64f21bcafa891105b468413f27431
  9. Affected versionversion=e9cb7be2fcbaee9e808b729e92948d38d52e5add

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <b62c510f59803f82f9b4c76ead2a56833b2984c7; version=368ba06881c395f1c9a7ba22203cf8d78b4addc0 <cfc0b8e5080aec87700774e8568765eaa4b7b92b; version=5.15.145 <5.16; version=543c12c2644e772caa6880662c2a852cfdc5a10c; version=6.1.34 <6.2; version=6.3.8 <6.4; version=6.4; version=df3a4518aee64f21bcafa891105b468413f27431; version=e9cb7be2fcbaee9e808b729e92948d38d52e5add

Published CVSS scores

9.1Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

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

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

CWE-125Out-of-bounds Read
T1210Exploitation of Remote Services

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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