# nfsd: release path refs on follow_down() error

CVE record · `CVE-2026-89707`

- **Identifiers:** `CVE-2026-89707`
- **State:** Confirmed
- **Severity:** CVSS 7.5 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, 19:46 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.

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before bdf5a0f88d21239d8f9f7519b87359ba95fd045c` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before 18847cbf5900f5c6c55bef5a6f7a34a1918d1181` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before e301c5cdb0dc2c4aeffc0c055ea15615d9c51fdc` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before 085cfde7c2186acaad103f02d2c25435ad5224e9` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before 194316df81263519156ebe714c4a286bee00e5be` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before 467d56fd3ff57447a790c6dc3ede2d02a947d224` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before 2bc4343308d85ee4e0dd3877b384306c96f114c2` (git)
  - affected: `cc53ce53c86924bfe98a12ea20b7465038a08792 to before 6cba08dc1922140d260cfeb30bbda4ee1bf869d8` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.38`
  - unaffected: `before 2.6.38` (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: `6.6.157 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's NFS server (nfsd) is vulnerable in multiple version ranges, starting from commit cc53ce53c86924bfe98a12ea20b7465038a08792 and affecting 2.6.38 onward until fixed. When a cross-mount operation fails, nfsd does not release references it took on a path, leaking them. Any authenticated NFS client can trigger repeated leaks, which can prevent unmounting and pin dentries in memory. Upgrade to a fixed kernel: 5.10.273 or later in the 5.10 series, 5.15.224 or later in 5.15, 6.1.191 or later in 6.1, or 6.6.157 or later in 6.6. The source gives no workaround.

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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0070, the 53rd 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-2026-89707](https://www.cve.org/CVERecord?id=CVE-2026-89707)
- [NVD: CVE-2026-89707](https://nvd.nist.gov/vuln/detail/CVE-2026-89707)

### References from the CNA

- <https://git.kernel.org/stable/c/bdf5a0f88d21239d8f9f7519b87359ba95fd045c>
- <https://git.kernel.org/stable/c/18847cbf5900f5c6c55bef5a6f7a34a1918d1181>
- <https://git.kernel.org/stable/c/e301c5cdb0dc2c4aeffc0c055ea15615d9c51fdc>
- <https://git.kernel.org/stable/c/085cfde7c2186acaad103f02d2c25435ad5224e9>
- <https://git.kernel.org/stable/c/194316df81263519156ebe714c4a286bee00e5be>
- <https://git.kernel.org/stable/c/467d56fd3ff57447a790c6dc3ede2d02a947d224>
- <https://git.kernel.org/stable/c/2bc4343308d85ee4e0dd3877b384306c96f114c2>
- <https://git.kernel.org/stable/c/6cba08dc1922140d260cfeb30bbda4ee1bf869d8>

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-2026-89707>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

---

The web page: <https://agentprime.io/advisories/CVE-2026-89707/>. Everything for agents: <https://agentprime.io/llms.txt>.