CVE-2026-64598Network attack vector

Kernel crash via truncated AEAD error code

Published Aug 6, 2026 · Updated Aug 6, 2026

Denial of service in the Linux kernel SMB client allows remote attackers to crash the system through encrypted SMB3 traffic. smb2_aead_req_alloc passes a negative scatter-gather count stored as u32 to ERR_PTR, producing an invalid pointer that later escapes error handling and is dereferenced. A user must mount or use an untrusted encrypted SMB3 share; the documented consequence is a kernel crash.

CVSS severity8.8
High
EPSS probability0.28%
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

Denial of service in the Linux kernel SMB client allows remote attackers to crash the system through encrypted SMB3 traffic. smb2_aead_req_alloc passes a negative scatter-gather count stored as u32 to ERR_PTR, producing an invalid pointer that later escapes error handling and is dereferenced. A user must mount or use an untrusted encrypted SMB3 share; the documented consequence is a kernel crash.

The record

CVE
CVE-2026-64598
Published
Aug 6, 2026
Updated
Aug 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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=6.3
  2. Affected versionversion=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <61f28012e5650c619223decdb7970e0d3162e949
  3. Affected versionversion=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <a187883cc1dc784a4d32537f5d316f1b7b9ad76f
  4. Affected versionversion=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <a1cc432cb0b0a1f74f98a0db3b94ca880c7947ac
  5. Affected versionversion=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <aa37f5fef78dd11cbf983269da2031e12625c56d
  6. Affected versionversion=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <cad756733dc3985188983f3e2eb77e2927209099

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.3; version=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <61f28012e5650c619223decdb7970e0d3162e949; version=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <a187883cc1dc784a4d32537f5d316f1b7b9ad76f; version=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <a1cc432cb0b0a1f74f98a0db3b94ca880c7947ac; version=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <aa37f5fef78dd11cbf983269da2031e12625c56d; version=d08089f649a0cfb2099c8551ac47eef0cc23fdf2 <cad756733dc3985188983f3e2eb77e2927209099

Published CVSS scores

8.8Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7OracleCVSS:3.1/AV:L/AC:H/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

T1499Endpoint Denial of Service

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