# nfsd: gate nfs3 setacl by argp->mask

CVE record · `CVE-2026-89671`

- **Identifiers:** `CVE-2026-89671`
- **State:** Confirmed
- **Severity:** CVSS 9.1 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:45 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.1: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to before beeb33152873ad40692bd255b562966f8ba43dbd` (git)
  - affected: `a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to before 3be1d8611dae4829e4608007db29f4a8748c37b2` (git)
  - affected: `a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to before 68a80b26efdff1d09f8ae1773c6a915abb9e191d` (git)
  - affected: `a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to before b3bff820d068ea59767d4e91a3258231a879da5f` (git)
  - affected: `a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to before ff99ed007f065198fd723152405c22aa558f700b` (git)
  - affected: `a257cdd0e2179630d3201c32ba14d7fcb3c3a055 to before 453d7198a0ab07a12d46e0575861ac7b932da17e` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.13`
  - unaffected: `before 2.6.13` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.157 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.109 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.50 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.4 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The Linux kernel NFS server (nfsd) is affected in its NFSv3 SETACL handling, from version 2.6.13 until fixed. A client able to send NFSv3 SETACL requests can silently remove a directory's default ACL, or both ACLs. Upgrade to Linux kernel 6.1.191, 6.6.157, 6.12.109, 6.18.50, or a later release in those series.

Written 12 Nov 2026.

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.1 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0054, the 46th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 11 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89671](https://www.cve.org/CVERecord?id=CVE-2026-89671)
- [NVD: CVE-2026-89671](https://nvd.nist.gov/vuln/detail/CVE-2026-89671)

### References from the CNA

- <https://git.kernel.org/stable/c/beeb33152873ad40692bd255b562966f8ba43dbd>
- <https://git.kernel.org/stable/c/3be1d8611dae4829e4608007db29f4a8748c37b2>
- <https://git.kernel.org/stable/c/68a80b26efdff1d09f8ae1773c6a915abb9e191d>
- <https://git.kernel.org/stable/c/b3bff820d068ea59767d4e91a3258231a879da5f>
- <https://git.kernel.org/stable/c/ff99ed007f065198fd723152405c22aa558f700b>
- <https://git.kernel.org/stable/c/453d7198a0ab07a12d46e0575861ac7b932da17e>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89671>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89671/>. Everything for agents: <https://agentprime.io/llms.txt>.