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.
Published: 2026-07-25
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The CVE targets the XFS filesystem’s quota iterator. When the 32‑bit identifier counter reaches XFS_DQ_ID_MAX, the addition operation overflows and wraps to zero, causing the iteration to restart from the beginning of the quota list. Based on the description, it is inferred that an attacker could exploit the wrap‑around to skip quota checks for files or users associated with the maximum identifier, potentially allowing them to consume disk space beyond their allocated quota.

Affected Systems

All Linux kernel deployments that use the XFS filesystem and include the dqiterate routine are affected. The flaw exists in any kernel where the routine performs the counter increment without converting the value to 64 bits; no specific kernel versions are listed, so any kernel lacking the patch is vulnerable.

Risk and Exploitability

The CVSS score of 5.5 indicates a moderate severity, and the EPSS score of less than 1% suggests low exploitation probability. The vulnerability is not listed in CISA's KEV catalog. Based on the description, the likely attack vector involves local access to a filesystem containing a dquot with the maximum ID and the ability to trigger the quota iterator; thus the exploitation requires privileged local access and is a moderate effort to achieve.

Generated by OpenCVE AI on August 13, 2026 at 10:58 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the Linux kernel to a version that includes the patch converting the q_id counter to a 64‑bit integer.
  • Restart the affected systems so the new kernel is loaded and the fix is active.
  • Until the kernel update is applied, avoid creating or using XFS quotas that reference the maximum ID value to reduce the risk of quota bypass.

Generated by OpenCVE AI on August 13, 2026 at 10:58 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4724-1 linux-6.12 new package
History

Wed, 12 Aug 2026 16:00:00 +0000

Type Values Removed Values Added
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.2:rc3:*:*:*:*:*:*

Thu, 30 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Sun, 26 Jul 2026 03:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-190

Sat, 25 Jul 2026 09:30:00 +0000

Type Values Removed Values Added
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.
Title xfs: don't wrap around quota ids in dqiterate
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-25T08:49:08.676Z

Reserved: 2026-07-19T15:36:31.773Z

Link: CVE-2026-64256

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2026-07-25T10:17:04.630

Modified: 2026-08-12T15:53:16.767

Link: CVE-2026-64256

cve-icon Redhat

Severity : Low

Publid Date: 2026-07-25T00:00:00Z

Links: CVE-2026-64256 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-13T11:00:12Z

Weaknesses