CVE-2026-89777: Linux kernel · vfio/pci: clear vdev->msi_perm after freeing it on init failure vfio_msi_cap_len()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 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:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 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 properly NULLs the vdev->msi_perm pointer after it is freed on initialization failure, preventing use-after-free and double free. Users should update to a patched Linux kernel version that includes this fix. Since this is a kernel vulnerability, applying the official kernel update from the vendor or distribution is the recommended remediation.
Description
CVE-2026-89777 is a use-after-free vulnerability in the Linux kernel's vfio/pci driver where a pointer to a freed MSI permission table is not cleared after an initialization failure. This leads to reuse and double free of the same memory, causing potential kernel crashes or memory corruption. The issue occurs because the pointer vdev->msi_perm is freed but not NULLed, allowing stale references to persist across device open/close cycles. The vulnerability has a CVSS score of 8.8, indicating high severity with impacts on confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2026-89777 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89777 (opens in a new tab)
- git.kernel.org/linus/dc77acfeb979dded39b247b60fef0399536bfa77 (opens in a new tab)
- git.kernel.org/stable/c/25cdd2a492d868cff1e519a60fe282909c52d385 (opens in a new tab)
- git.kernel.org/stable/c/533d0c5feef85ee6404b9f41d5564fac6971a008 (opens in a new tab)
- git.kernel.org/stable/c/812f1db7f0755a19ef16ecdc5cec51bcabc5eda5 (opens in a new tab)
- git.kernel.org/stable/c/d665a1688af7f8fefd7c0eb04f2a37122ce007f4 (opens in a new tab)
- git.kernel.org/stable/c/dc77acfeb979dded39b247b60fef0399536bfa77 (opens in a new tab)
- git.kernel.org/stable/c/eb84cd81040e58dd05ac190f561f2115e3367249 (opens in a new tab)
- git.kernel.org/stable/c/f0eea8f9013676b42289ec35941e848b8a543e19 (opens in a new tab)
- git.kernel.org/stable/c/fda8fb7e8179561693a786a7af593f6b944a21c1 (opens in a new tab)