CVE-2026-74307: Linux kernel · ext4: validate donor file superblock early in EXT4_IOC_MOVE_EXT
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 7.0.0-1014.14~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +11
Exploitation 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.
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
An official fix is available and should be applied. The patch moves the donor file superblock validation earlier in the ioctl handling to prevent deadlocks. Systems running affected Linux kernel versions should update to a fixed version as provided by their vendor. No additional mitigations are required beyond applying the official patch.
Description
A vulnerability in the Linux kernel's ext4 filesystem implementation was resolved by validating the donor file's superblock early in the EXT4_IOC_MOVE_EXT ioctl operation. The flaw allowed a circular lock dependency and potential deadlock when the donor file descriptor referred to a file on a different filesystem, such as overlayfs. The fix moves the superblock validation before any inode locks or sb_writers locks are acquired, preventing the deadlock scenario.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74307 (opens in a new tab)
- git.kernel.org/stable/c/74796e886ca39fcb0d3fd36ea6a39c62784ab6fb (opens in a new tab)
- git.kernel.org/stable/c/c143957520c6c9b5cd72e0de8b52b814f0c576fe (opens in a new tab)
- git.kernel.org/stable/c/fb52013cad9e9b7d3a6a14ea1bcd841e41da7c6c (opens in a new tab)
- ubuntu.com/security/CVE-2026-74307 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74307 (opens in a new tab)
- git.kernel.org/linus/c143957520c6c9b5cd72e0de8b52b814f0c576fe (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)