CVE-2026-64557: Linux kernel · Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 6.8.0-147.147 : patch Linux kernel soon.
Data as of 28 Oct 2026, 03:15 UTC
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1014.14~24.04.1 +26
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (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 applied in multiple Linux kernel versions including 6.8.0-147.147 and later. Users and administrators should update to these fixed kernel versions to remediate the vulnerability. No additional mitigation steps are required beyond applying the official fix.
Description
CVE-2026-64557 is a high-severity use-after-free vulnerability in the Linux kernel's Bluetooth L2CAP subsystem. The flaw occurs in the l2cap_sock_new_connection_cb() function where a child socket can be freed by another task before the callback dereferences it, leading to a use-after-free condition. The issue was addressed by changing the ownership model of the child channel's lifetime and consolidating channel configuration. Multiple Linux kernel versions prior to 6.8.0-147.147 and related builds are affected. A patch is available and has been applied in fixed versions.
References
- ubuntu.com/security/CVE-2026-64557 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64557 (opens in a new tab)
- git.kernel.org/linus/6fef032af0092ed5ccb767239a9ac1bc38c08a40 (opens in a new tab)
- git.kernel.org/stable/c/36da806f7fbaee56ad9e81859deec203f9728700 (opens in a new tab)
- git.kernel.org/stable/c/6fef032af0092ed5ccb767239a9ac1bc38c08a40 (opens in a new tab)
- git.kernel.org/stable/c/733e76e74e406c1d1ddc7369420dd8a47f48bb8a (opens in a new tab)
- git.kernel.org/stable/c/84e718b6a814edc84159361f9f454a4e92ae91ae (opens in a new tab)
- git.kernel.org/stable/c/8c37e4338c801ebb8cee52436c01c41e009f6e87 (opens in a new tab)
- git.kernel.org/stable/c/b39298044e5534612511a2ff5de03ba5f6e7a820 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (opens in a new tab)