CVE-2026-64368: Linux kernel · mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in 6.8.0-147.147 : patch Linux kernel soon.
Data as of 6 Nov 2026, 17:27 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:N/AC:H/PR:N/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 released in multiple Linux kernel versions including 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1, and others. Users and administrators should update to these fixed kernel versions to remediate the vulnerability. No additional mitigation steps are required beyond applying the official kernel updates.
Description
CVE-2026-64368 is a vulnerability in the Linux kernel's memory management slab allocator related to zeroing behavior when only red zoning is enabled. The flaw causes improper zeroing of memory allocations, potentially violating the guarantees expected by the krealloc() function when __GFP_ZERO is requested. This occurs because the check for tracking requested size is imprecise, leading to zeroing beyond the requested size when only SLAB_RED_ZONE is enabled without SLAB_STORE_USER. The issue has been fixed by refining the check to correctly detect when requested size tracking is enabled.
References
- ubuntu.com/security/CVE-2026-64368 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64368 (opens in a new tab)
- git.kernel.org/linus/648927ceb84021a25a0fbd5673740956f318d534 (opens in a new tab)
- git.kernel.org/stable/c/0d18ccef142f04433dfb2a0c120cf223d2b8a42c (opens in a new tab)
- git.kernel.org/stable/c/2382971aaaef5bf85a651234c64906f59580b8be (opens in a new tab)
- git.kernel.org/stable/c/6256899c3a34674bba6076884aedbba49fc695e4 (opens in a new tab)
- git.kernel.org/stable/c/648927ceb84021a25a0fbd5673740956f318d534 (opens in a new tab)
- git.kernel.org/stable/c/7e706d50fa119eead6376bf0ef973e8d73a96030 (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)