# smb: client: clear setuid/setgid bit on write with cifsacl/modefromsid/posix extensions

CVE record · `CVE-2026-89638`

- **Identifiers:** `CVE-2026-89638`
- **State:** Confirmed
- **Severity:** CVSS 7.8 High
- **Critical:** No
- **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.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before ce0e675907b887db2b1e44a806118b0a7d8b6b18` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before a3a0cc83761e46a75b1ed6bfaf35961f2c211148` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before 2a5206992f526178881e8f5c4644757c336fb76d` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before 7ceb6f7cb8f8f2b094e0dcdaf75757775d231378` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before 58b23fc9fb580432470d6c5da3c1e5660dba9fbc` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before b10015807e4c628095d1d1d1c9307efc8cdd9e1b` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before 69bfe810ecd1e0387d8975d711cd326341d13c6e` (git)
  - affected: `d32c4f2626acc385d5187bd5c0c24f442328dc60 to before b8e5dc4f95e5484159b343903f302eb6d783f2e6` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.24`
  - unaffected: `before 2.6.24` (semver)
  - unaffected: `5.10.273 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.224 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.160 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.113 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.51 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

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0018, the 7th 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-2026-89638](https://www.cve.org/CVERecord?id=CVE-2026-89638)
- [NVD: CVE-2026-89638](https://nvd.nist.gov/vuln/detail/CVE-2026-89638)

### References from the CNA

- <https://git.kernel.org/stable/c/ce0e675907b887db2b1e44a806118b0a7d8b6b18>
- <https://git.kernel.org/stable/c/a3a0cc83761e46a75b1ed6bfaf35961f2c211148>
- <https://git.kernel.org/stable/c/2a5206992f526178881e8f5c4644757c336fb76d>
- <https://git.kernel.org/stable/c/7ceb6f7cb8f8f2b094e0dcdaf75757775d231378>
- <https://git.kernel.org/stable/c/58b23fc9fb580432470d6c5da3c1e5660dba9fbc>
- <https://git.kernel.org/stable/c/b10015807e4c628095d1d1d1c9307efc8cdd9e1b>
- <https://git.kernel.org/stable/c/69bfe810ecd1e0387d8975d711cd326341d13c6e>
- <https://git.kernel.org/stable/c/b8e5dc4f95e5484159b343903f302eb6d783f2e6>

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-2026-89638>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89638/>. Everything for agents: <https://agentprime.io/llms.txt>.