CVE-2026-72221: Linux kernel · sunrpc: wait for in-flight TLS handshake callback when cancel loses race
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 6.8.0-147.147 : patch Linux kernel as a priority.
Data as of 28 Oct 2026, 05:11 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 50% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1013.13~24.04.1 +27
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (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 vendor-provided patch is available and should be applied promptly to affected Linux kernel versions. The fixed versions include 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1013.13~24.04.1, and others as listed in the established facts. Users should update to these fixed kernel releases to remediate the vulnerability. No alternative mitigations or workarounds are indicated by the vendor advisory.
Description
CVE-2026-72221 is a critical race condition vulnerability in the Linux kernel's sunrpc subsystem related to TLS handshake cancellation. The flaw occurs when the kernel does not properly wait for an in-flight TLS handshake callback to complete before proceeding, leading to two race conditions that can cause session mismanagement or connection teardown despite a successful handshake. This can result in corruption of internal kernel structures and potentially compromise system stability or security. The issue affects multiple Linux kernel versions prior to fixed releases in the 6.8 and 7.0 series and several specific older versions. A patch is available and has been released by the vendor.
References
- ubuntu.com/security/CVE-2026-72221 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72221 (opens in a new tab)
- git.kernel.org/linus/d00e32f84ca1a77cb67a3fbf59f58dada95f5a21 (opens in a new tab)
- git.kernel.org/stable/c/0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9 (opens in a new tab)
- git.kernel.org/stable/c/65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b (opens in a new tab)
- git.kernel.org/stable/c/a4f878e8ecd729ccf2e50993444e217583adeace (opens in a new tab)
- git.kernel.org/stable/c/d00e32f84ca1a77cb67a3fbf59f58dada95f5a21 (opens in a new tab)
- git.kernel.org/stable/c/e0f4691d42a54d359d8b64509fd9ab938d4f2a33 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (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)