CVE-2026-89601: Linux kernel · ext2: Fix lost inode updates for IS_SYNC inodes
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 28 Oct 2026, 01:01 UTC
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 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.
Description
In the Linux kernel, the following vulnerability has been resolved: ext2: Fix lost inode updates for IS_SYNC inodes ext2_setsize() and ext2_xattr_set2() had a construct like: if (IS_SYNC(inode)) { sync_inode_metadata(inode, 1); } else { mark_inode_dirty(inode); } which leads to lost inode updates for IS_SYNC inodes because sync_inode_metadata() does anything only if the inode is already dirty and hence inode updates may be simply lost. Fix the problem by unconditionally marking the inode dirty and *then* call sync_inode_metadata().
References
- ubuntu.com/security/CVE-2026-89601 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89601 (opens in a new tab)
- git.kernel.org/linus/356984d1a5c32e94810cbb6c8dc7d8ff2d4d919a (opens in a new tab)
- git.kernel.org/stable/c/356984d1a5c32e94810cbb6c8dc7d8ff2d4d919a (opens in a new tab)
- git.kernel.org/stable/c/5efb3350230fef831167740e69e6db2861101186 (opens in a new tab)