CVE-2026-64402: Linux kernel · coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-147.147 : patch Linux kernel soon.
Data as of 6 Nov 2026, 17:25 UTC
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1 +30
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and has been incorporated into Linux kernel versions 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1, 6.8.0-1071.79, 7.0.0-1014.14~24.04.1, and others as listed in the fixedVersions. Users and administrators should update to these fixed kernel versions to remediate the vulnerability.
Description
A vulnerability in the Linux kernel's coresight ultrasoc-smb component allows an out-of-bounds write in the smb_sync_perf_buffer() function. This occurs when the SMB sink is used as a perf AUX sink and the page index calculation does not properly normalize the head pointer before indexing, potentially leading to memory corruption. The issue has been fixed in multiple Linux kernel versions.
References
- ubuntu.com/security/CVE-2026-64402 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64402 (opens in a new tab)
- git.kernel.org/linus/98495b5a4d77dd22e106f462b76e1093a55b29a7 (opens in a new tab)
- git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b (opens in a new tab)
- git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1 (opens in a new tab)
- git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb (opens in a new tab)
- git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7 (opens in a new tab)
- git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)