CVE-2026-74595: Linux kernel · fscrypt: use the mount idmap for the owner check in fscrypt_ioctl_set_policy()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High : upgrade to 6.8.0-1036.39 soon.
Data as of 28 Oct 2026, 01:00 UTC
- Patch
- Available – fixed in 6.8.0-1036.39
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 22 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 the Ubuntu linux-nvidia-tegra package to 6.8.0-1036.39.
Patches and advisories
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: fscrypt: use the mount idmap for the owner check in fscrypt_ioctl_set_policy() fscrypt_ioctl_set_policy() calls inode_owner_or_capable() with &nop_mnt_idmap before allowing an encryption policy to be set, instead of the idmap of the mount the ioctl was issued on. fscrypt is used by filesystems that support idmapped mounts (e.g. ext4, f2fs), so on such a mount this compares the caller's fsuid against the unmapped on-disk owner rather than the mapped owner: the actual owner can be wrongly denied with -EACCES and an unrelated caller wrongly allowed. Use file_mnt_idmap(filp) instead.
References
- ubuntu.com/security/CVE-2026-74595 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74595 (opens in a new tab)
- git.kernel.org/stable/c/33b7e810ce09955aa02f3b632455cf5e7ac990a9 (opens in a new tab)
- git.kernel.org/stable/c/cf6c993c0feca7984797e634deba3c80342e199a (opens in a new tab)
- git.kernel.org/stable/c/6a67c460b12315033268dce597546984fe5739e7 (opens in a new tab)
- git.kernel.org/stable/c/98516ba8b817f34e86bdd7a5b7a383cff75c3ddf (opens in a new tab)
- git.kernel.org/stable/c/0baeb730044981f5ec5fb7d62a3763835ea606f6 (opens in a new tab)
- git.kernel.org/stable/c/653e888a24c87b8bbeab44d7e558a1c1a3641088 (opens in a new tab)
- git.kernel.org/stable/c/174633a468817a49bd474bcfc9067c84e54efe68 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)