fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup…
Priority LOW 31Published · Updated
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for those servers to be unreachable during trunking detection.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01245 69th percentileScored 2026-11-08
Fix Deferred Red Hat: fix deferred
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.13.4 | Vulnerable | Linux |
| cpe:2.3:o:netapp:hci_bootstrap_os:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:hci_compute_node:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:a:netapp:element_software:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:hci_storage_node:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.13.4 Vulnerable ·Linux
- cpe:2.3:o:netapp:hci_bootstrap_os:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:hci_compute_node:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:a:netapp:element_software:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:hci_storage_node:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-38199
- 2026-10-03 Alias added: GHSA-2crj-6275-fwfr
- 2026-10-08 CISA SSVC decision points changed
References
Patch 2
Sources
- CVE-2021-38199 · CVE Program
- CVE-2021-38199 · NVD
- FIRST EPSS
- GHSA-2crj-6275-fwfr · GitHub Advisory Database · CC BY 4.0
- CVE-2021-38199 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences