CVE-2026-64534: Linux kernel · nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 25% 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 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.
AI-suggested
A patch is available and should be applied to affected linux-hwe-edge kernel versions. The vendor advisory confirms that this issue has been resolved. Users should update to the fixed kernel versions to mitigate this vulnerability.
Description
A use-after-free vulnerability in the Linux kernel's nvmet-tcp subsystem was resolved by adding a check for the INIT_FAILED flag before calling nvmet_req_uninit() in the digest error path. Without this check, a refcount underflow could occur, leading to a warning, diagnostic errors, and a permanent workqueue deadlock. This vulnerability affects specific linux-hwe-edge kernel versions and has a high CVSS score of 9.8.
References
- ubuntu.com/security/CVE-2026-64534 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64534 (opens in a new tab)
- git.kernel.org/linus/4606467a75cfc16721937272ed29462a750b60c8 (opens in a new tab)
- git.kernel.org/stable/c/22ec7a9fe9153d2737ee9b2fa6d2e43a1491decf (opens in a new tab)
- git.kernel.org/stable/c/2ed3c9d955e8cd6361f130623baa664a75fb345f (opens in a new tab)
- git.kernel.org/stable/c/4606467a75cfc16721937272ed29462a750b60c8 (opens in a new tab)
- git.kernel.org/stable/c/ba35b1c674ca3841c0dfadd698f2c1b3ec542d4e (opens in a new tab)
- git.kernel.org/stable/c/c7874dad84b20433c0fe3919f291a762d40de08b (opens in a new tab)
- git.kernel.org/stable/c/d306da8833e75f669d93424fd84940236f3850bc (opens in a new tab)
- git.kernel.org/stable/c/e602c93b25bda4a9d0ff1791a4bdbfdcbb074af1 (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-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)