CVE-2026-74494Network attack vector

Unauthenticated denial of service via repeated negotiation

Published Aug 15, 2026 · Updated Aug 15, 2026

Memory leak in Linux ksmbd allows remote attackers to exhaust kernel memory through repeated pre-session SMB2 NEGOTIATE requests. The smb2_handle_negotiate() path accepts another SMB3.1.1 negotiation while the connection awaits session setup, replaces conn->preauth_info, and frees only the final allocation. An unauthenticated network client can repeat the request before SESSION_SETUP, consuming memory until the service or host becomes unavailable.

CVSS severity7.5
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in Linux ksmbd allows remote attackers to exhaust kernel memory through repeated pre-session SMB2 NEGOTIATE requests. The smb2_handle_negotiate() path accepts another SMB3.1.1 negotiation while the connection awaits session setup, replaces conn->preauth_info, and frees only the final allocation. An unauthenticated network client can repeat the request before SESSION_SETUP, consuming memory until the service or host becomes unavailable.

The record

CVE
CVE-2026-74494
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-772, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=5.15
  2. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <7e02cb30e8a1f5fc78cb10b220b06020e36d0bbe
  3. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <a60b5da05e318d9a364dbac38c347c7f24e625e7
  4. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <cb469993b3a61a72653770856d37af616d72d05f

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <7e02cb30e8a1f5fc78cb10b220b06020e36d0bbe; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <a60b5da05e318d9a364dbac38c347c7f24e625e7; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <cb469993b3a61a72653770856d37af616d72d05f

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.5Amazon LinuxCVSS:3.1/AV:N/AC:L/PR:N/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-772Missing Release of Resource after Effective Lifetime
T1499.003Application Exhaustion Flood

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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