Live › vulnerability › CVE-2026-99131
Go to dashboardThe Linux kernel XFS filesystem checked the wrong credential set for a capability, so a user could change a file's group ID to another group they belong to and skip quota accounting. The result is that a user can exceed a group's quota hard limit.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-28 11:32 UTC. All times on this page are UTC.
Systems running a Linux kernel with XFS filesystems and group quotas enforced, particularly where file attributes are changed through an NFS client. Systems without XFS quotas enforced, or that do not use XFS, are unlikely to be affected. The sources do not give affected kernel version ranges.
No product ranges from the sources yet.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix capability check in xfs
An user reported a bug where he managed to evade group's quota by changing a file's gid to a different group id the same user belonged to, even though quotas were enforced on both gids and the file's size was big enough to exceed the quota's hardlimit.
Commit eba0549bc7d1 replaced a capable() call by a has_capability_noaudit() to prevent unnecessary selinux audit messages. Turns out that both calls have slightly different semantics even though their documentation seems similar. Where in a nutshell:
capable() - Tests the task's effective credentials has_ns_capability_noaudit() - Tests the task's real credentials
This most of the time has no practical difference but in some cases like changing attrs (specifically group id in this case) through a NFS client this will allow the quota code to use XFS_QMOPT_FORCE_RES, effectively bypassing quota accounting checks.
Using instead ns_capable_noaudit() should fix this issue and prevent selinux audit messages.
This also fix the remaining calls to has_capability_noaudit()
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