# NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers

CVE record · `CVE-2026-90149`

- **Identifiers:** `CVE-2026-90149`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 17 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 17 Sept 2026, 16:06 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: `a7878ca140084ec267ede48fce64d7e60f6d873e to before e55d7fec8a9290f73032ee34c35dd68532809633` (git)
  - affected: `a7878ca140084ec267ede48fce64d7e60f6d873e to before 336b6da10021c69a8f273bbacdf7432fdc89a06f` (git)
  - affected: `a7878ca140084ec267ede48fce64d7e60f6d873e to before 5527af72b0100c94287bfec901b6313eeac567ca` (git)
  - affected: `a7878ca140084ec267ede48fce64d7e60f6d873e to before 163c16e01f53fc8eb8d0f3484ae6c382265ecbbd` (git)
  - affected: `a7878ca140084ec267ede48fce64d7e60f6d873e to before 436a214514e24103159aea455147d58b44a8a585` (git)
  - affected: `a7878ca140084ec267ede48fce64d7e60f6d873e to before 2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `4.12`
  - unaffected: `before 4.12` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.160 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.114 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.52 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.6 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 NFSv4 flexfiles client is affected from 4.12 until fixed when it uses NFSv4.0 data servers. I/O to such a data server can trigger a NULL pointer dereference and kernel oops. The source gives few details on what access an attacker needs. Upgrade to 6.1.191, 6.6.160, 6.12.114, or 6.18.52, 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

- 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:** 0.0066, the 52nd percentile, on 13 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 17 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-90149](https://www.cve.org/CVERecord?id=CVE-2026-90149)
- [NVD: CVE-2026-90149](https://nvd.nist.gov/vuln/detail/CVE-2026-90149)

### References from the CNA

- <https://git.kernel.org/stable/c/e55d7fec8a9290f73032ee34c35dd68532809633>
- <https://git.kernel.org/stable/c/336b6da10021c69a8f273bbacdf7432fdc89a06f>
- <https://git.kernel.org/stable/c/5527af72b0100c94287bfec901b6313eeac567ca>
- <https://git.kernel.org/stable/c/163c16e01f53fc8eb8d0f3484ae6c382265ecbbd>
- <https://git.kernel.org/stable/c/436a214514e24103159aea455147d58b44a8a585>
- <https://git.kernel.org/stable/c/2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc>

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-2026-90149>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-90149/>. Everything for agents: <https://agentprime.io/llms.txt>.