# smb: client: reject userspace cifs.idmap descriptions

CVE record · `CVE-2026-97564`

- **Identifiers:** `CVE-2026-97564`
- **State:** Confirmed
- **Severity:** No CVSS score
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 25 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 25 Sept 2026, 10:21 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: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before 91da70a2e5c6f54e1316d51e0e6911e78ef5e09a` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before 856cb3f05b49d23dc1542f78696e20c4ea6dd7de` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before 17c93bcd17755523c21abb22cbf2a41a6eb0caaf` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before e5964064e3fbe6325893408faff08ca33de0e2c3` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before 96751028c0d4dec785709ea3eb0ab38a4f2ded96` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before 1d3b24b16a0b013792e8f1e3ed060f0b46f537d1` (git)
  - affected: `4d79dba0e00749fa40de8ef13a9b85ce57a1603b to before d9d7eeb0cea5b55b82888f443622fd8d4ee064f3` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `3.0`
  - unaffected: `before 3.0` (semver)
  - unaffected: `5.10.273 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.224 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.189 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.158 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.111 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.53 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.7 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.

> Linux kernel CIFS (the cifs.idmap key type) accepts key descriptions created from userspace, affecting kernels from 3.0 until fixed in each stable branch. A local user who can call add_key(2) or request_key(2) can supply these fields and trigger a root-context usermodehelper upcall. Upgrade to 5.10.273, 5.15.224, 6.1.189, 6.6.158 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

No source has published a CVSS score for this record yet.

- **CISA KEV:** Not listed.
- **EPSS:** 0.0022, the 12th percentile, on 12 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 25 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-97564](https://www.cve.org/CVERecord?id=CVE-2026-97564)
- [NVD: CVE-2026-97564](https://nvd.nist.gov/vuln/detail/CVE-2026-97564)

### References from the CNA

- <https://git.kernel.org/stable/c/91da70a2e5c6f54e1316d51e0e6911e78ef5e09a>
- <https://git.kernel.org/stable/c/856cb3f05b49d23dc1542f78696e20c4ea6dd7de>
- <https://git.kernel.org/stable/c/f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a>
- <https://git.kernel.org/stable/c/17c93bcd17755523c21abb22cbf2a41a6eb0caaf>
- <https://git.kernel.org/stable/c/e5964064e3fbe6325893408faff08ca33de0e2c3>
- <https://git.kernel.org/stable/c/96751028c0d4dec785709ea3eb0ab38a4f2ded96>
- <https://git.kernel.org/stable/c/1d3b24b16a0b013792e8f1e3ed060f0b46f537d1>
- <https://git.kernel.org/stable/c/d9d7eeb0cea5b55b82888f443622fd8d4ee064f3>

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-2026-97564>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-97564/>. Everything for agents: <https://agentprime.io/llms.txt>.