CVE-2026-90325: Linux kernel · blk-cgroup: skip dying blkg in blkcg_activate_policy()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 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
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 fix is available that adds a check to skip processing block groups that are already being destroyed, preventing the use-after-free. Users should apply the official Linux kernel updates that include this patch. Since this is a kernel vulnerability, updating to a patched kernel version is the recommended remediation.
Description
A use-after-free vulnerability in the Linux kernel's blk-cgroup subsystem was resolved. The flaw occurs during IO scheduler switching on a block device, where a race condition between blkcg_activate_policy() and concurrent blkcg deletion can lead to use-after-free in rcu_accelerate_cbs. The fix involves checking if a block group (blkg) is already being destroyed before referencing it, preventing access to freed memory.
References
- nvd.nist.gov/vuln/detail/CVE-2026-90325 (opens in a new tab)
- git.kernel.org/stable/c/083b58373463a6e5ee60ecb135269348f68ad7df (opens in a new tab)
- git.kernel.org/stable/c/1a267295b1ea6a6477963f3fda84adfecd48fcad (opens in a new tab)
- git.kernel.org/stable/c/3d8c3da95c75a4d312e272fc7b4076dd3ba9115c (opens in a new tab)
- git.kernel.org/stable/c/5e9220389920f33b6a804d50c548cd0cd1b04634 (opens in a new tab)
- git.kernel.org/stable/c/7337d012ca3fc3a6a2d1c8e2a19c6d97c38b410d (opens in a new tab)
- git.kernel.org/stable/c/b5dae1cd0d8368b4338430ff93403df67f0b8bcc (opens in a new tab)
- git.kernel.org/stable/c/d8c872901e6459339374e9eea80aa919176c2ccd (opens in a new tab)
- ubuntu.com/security/CVE-2026-90325 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90325 (opens in a new tab)
- git.kernel.org/linus/5e9220389920f33b6a804d50c548cd0cd1b04634 (opens in a new tab)