CVE-2026-64256: Linux kernel · xfs: don't wrap around quota ids in dqiterate
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 7.0.0-1012.12~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 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.
- Patch
- Available – fixed in 7.0.0-1012.12~24.04.1, 7.0.0-1011.11~24.04.1, 7.0.0-31.31~24.04.1 +7
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 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 patch is available and included in updated Linux kernel packages for Ubuntu 24.04 LTS and 26.04 LTS releases. Users should apply the kernel updates (versions 7.0.0-31.31 and later) and reboot their systems to ensure the vulnerability is remediated. Due to an ABI change, third-party kernel modules must be recompiled and reinstalled after updating. No additional mitigation steps are required beyond applying the official updates.
Description
In the Linux kernel, the following vulnerability has been resolved: xfs: don't wrap around quota ids in dqiterate LOLLM noticed that q_id is an unsigned 32-bit variable. If it happens to be set to XFS_DQ_ID_MAX due to a filesystem that actually has a dquot for ID_MAX, then this addition will truncate to zero and the iteration starts over. Fix this by casting to u64.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64256 (opens in a new tab)
- git.kernel.org/stable/c/249e311c2ba392ceaf9ebfc145a46922946f069a (opens in a new tab)
- git.kernel.org/stable/c/2b14fe1e0924c6b901f4256456342569c5397abe (opens in a new tab)
- git.kernel.org/stable/c/d1c4c40599c376aeb0c93068a2ae344e79ee4b90 (opens in a new tab)
- git.kernel.org/stable/c/d766e4e5e85d829629c3ba503802fe1303d7b591 (opens in a new tab)
- ubuntu.com/security/CVE-2026-64256 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64256 (opens in a new tab)
- git.kernel.org/linus/d766e4e5e85d829629c3ba503802fe1303d7b591 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)