CVE-2024-26594Network attack vector

Kernel heap disclosure via mechToken length mismatch

Published Feb 23, 2024 · Updated Aug 5, 2026

Out-of-bounds read in Linux ksmbd allows remote attackers to disclose kernel heap data via crafted SMB session-setup tokens. session_user and ntlm_authenticate bound reads from the decoded SPNEGO mechToken with the larger request SecurityBufferLength rather than the token's allocation size. The path is reachable before authentication when ksmbd serves SMB; repeated requests can expose heap contents and crash a worker or the kernel.

CVSS severity9.1
Critical
EPSS probability50.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in Linux ksmbd allows remote attackers to disclose kernel heap data via crafted SMB session-setup tokens. session_user and ntlm_authenticate bound reads from the decoded SPNEGO mechToken with the larger request SecurityBufferLength rather than the token's allocation size. The path is reachable before authentication when ksmbd serves SMB; repeated requests can expose heap contents and crash a worker or the kernel.

The record

CVE
CVE-2024-26594
Published
Feb 23, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1499, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=0626e6641f6b467447c81dd7678a69c66f7746cf <5e6dfec95833edc54c48605a98365a7325e5541e
  2. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <6eb8015492bcc84e40646390e50a862b2c0529c9
  3. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <92e470163d96df8db6c4fa0f484e4a229edb903d
  4. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <a2b21ef1ea4cf632d19b3a7cc4d4245b8e63202a
  5. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <dd1de9268745f0eac83a430db7afc32cbd62e84b
  6. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0626e6641f6b467447c81dd7678a69c66f7746cf <5e6dfec95833edc54c48605a98365a7325e5541e; version=0626e6641f6b467447c81dd7678a69c66f7746cf <6eb8015492bcc84e40646390e50a862b2c0529c9; version=0626e6641f6b467447c81dd7678a69c66f7746cf <92e470163d96df8db6c4fa0f484e4a229edb903d; version=0626e6641f6b467447c81dd7678a69c66f7746cf <a2b21ef1ea4cf632d19b3a7cc4d4245b8e63202a; version=0626e6641f6b467447c81dd7678a69c66f7746cf <dd1de9268745f0eac83a430db7afc32cbd62e84b; version=5.15

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
9.1Linux Kernel CVE TeamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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
T1499Endpoint Denial of Service
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo