CVE-2026-64370: Linux kernel · posix-cpu-timers: Fix pid refcount leak in do_cpu_nanosleep() error path
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +43
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 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.
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.
Description
In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: Fix pid refcount leak in do_cpu_nanosleep() error path In do_cpu_nanosleep(), posix_cpu_timer_create() takes a pid reference via get_pid() and stores it in timer.it.cpu.pid. If the subsequent posix_cpu_timer_set() call fails, the function returns immediately without calling posix_cpu_timer_del() to release the pid reference, causing a leak. Fix it by calling posix_cpu_timer_del() before the unlock-and-return on the error path, consistent with the other exit paths in the same function.
References
- ubuntu.com/security/CVE-2026-64370 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64370 (opens in a new tab)
- git.kernel.org/linus/87bd2ad568e15b90d5f7d4bcd70342d05dad649c (opens in a new tab)
- git.kernel.org/stable/c/7776f9226e99eb49d97492b0b445027cfcb189da (opens in a new tab)
- git.kernel.org/stable/c/87bd2ad568e15b90d5f7d4bcd70342d05dad649c (opens in a new tab)
- git.kernel.org/stable/c/8a270b1258797f61b61da44f8bfd41a581b5c85b (opens in a new tab)
- git.kernel.org/stable/c/8f06363446c5d043c9a7c008b250040e9de98cf9 (opens in a new tab)
- git.kernel.org/stable/c/afed3cdc1cca133f804fcf57ff228974f424b23a (opens in a new tab)
- git.kernel.org/stable/c/d605d00085adc3fddf67de01dc2a44aebf1a3fb5 (opens in a new tab)
- git.kernel.org/stable/c/e5ffc638faf5dc7d9dc85c9a95e10bf97442e0c0 (opens in a new tab)
- git.kernel.org/stable/c/eb4cec29a78334d09bcfb41c0660cdd62ba05843 (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)