# nfsd: RCU-protect cl_cb_session to fix use-after-free on session teardown

CVE record · `CVE-2026-89708`

- **Identifiers:** `CVE-2026-89708`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:46 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 9.8: 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: `dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 to before 2775ec1d617e665eab71ce0f13ab1f7959713a2b` (git)
  - affected: `dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 to before f164eb52b6f3cbf40f07fe379f9f421f88e02f76` (git)
  - affected: `dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 to before 13bdd486c3aad4fc19e6d8b9c3556a4b4c190b25` (git)
  - affected: `dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 to before 01c5d5f58a5db9b0ee5afba2e49d3157788687b2` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.38`
  - unaffected: `before 2.6.38` (semver)
  - unaffected: `6.12.111 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

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0044, the 39th 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-2026-89708](https://www.cve.org/CVERecord?id=CVE-2026-89708)
- [NVD: CVE-2026-89708](https://nvd.nist.gov/vuln/detail/CVE-2026-89708)

### References from the CNA

- <https://git.kernel.org/stable/c/2775ec1d617e665eab71ce0f13ab1f7959713a2b>
- <https://git.kernel.org/stable/c/f164eb52b6f3cbf40f07fe379f9f421f88e02f76>
- <https://git.kernel.org/stable/c/13bdd486c3aad4fc19e6d8b9c3556a4b4c190b25>
- <https://git.kernel.org/stable/c/01c5d5f58a5db9b0ee5afba2e49d3157788687b2>

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-2026-89708>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89708/>. Everything for agents: <https://agentprime.io/llms.txt>.