CVE-2026-98975: Linux kernel · xfs: stop exchanging reflink flags when exchanging mappings
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 28 Oct 2026, 01:59 UTC
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 23 Oct 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 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 for this vulnerability is available and has been applied in the Linux kernel. The patch stops exchanging reflink flags during extent exchanges and ensures both inodes maintain the reflink flag correctly. Users should update to a fixed kernel version that includes this patch to prevent data corruption. No additional mitigation steps are indicated beyond applying the official fix.
Description
CVE-2026-98975 is a vulnerability in the Linux kernel's XFS filesystem related to improper handling of reflink flags during extent exchanges between files. The flaw occurs when exchanging mappings that cover both files from offset 0 to the disk size, causing incorrect assumptions about shared blocks beyond the file size. This can lead to in-place writes instead of copy-on-write (CoW), resulting in corruption of shared data. The issue affects the XFS_IOC_SWAPEXT operation similarly, where reflink flags were improperly moved between inodes. The fix involves stopping the exchange of reflink flags and ensuring both inodes maintain the flag correctly. The vulnerability has a CVSS score of 7.8 (high severity).
References
- ubuntu.com/security/CVE-2026-98975 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98975 (opens in a new tab)
- git.kernel.org/stable/c/1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be (opens in a new tab)
- git.kernel.org/stable/c/4756c94260e69ce42612b8220c3614f02f7a11d5 (opens in a new tab)
- git.kernel.org/stable/c/7d3b9b2c9dc57f93f36c716ab752548cb4db9900 (opens in a new tab)
- git.kernel.org/stable/c/d84d6c1a7f1e2de9e601703a326a4c1b7b421943 (opens in a new tab)