CVE-2025-40212

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2025-11-24. the CNA's CVSS baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix refcount leak in nfsd_set_fh_dentry()

nfsd exports a "pseudo root filesystem" which is used by NFSv4 to find the various exported filesystems using LOOKUP requests from a known root filehandle. NFSv3 uses the MOUNT protocol to find those exported filesystems and so is not given access to the pseudo root filesystem.

If a v3 (or v2) client uses a filehandle from that filesystem, nfsd_set_fh_dentry() will report an error, but still stores the export in "struct svc_fh" even though it also drops the reference (exp_put()). This means that when fh_put() is called an extra reference will be dropped which can lead to use-after-free and possible denial of service.

Normal NFS usage will not provide a pseudo-root filehandle to a v3 client. This bug can only be triggered by the client synthesising an incorrect filehandle.

To fix this we move the assignments to the svc_fh later, after all possible error cases have been detected.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
34%
KEV
Not listed

Published

November 24, 2025

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

nfsd: fix refcount leak in nfsd_set_fh_dentry() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8a7348a9ed70bda1c1f51d3f1815bcbdf9f3b38c
generic

nfsd: fix refcount leak in nfsd_set_fh_dentry() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c83d7365cec5eb5ebeeee2a72e29b4ca58a7e4c2
generic

nfsd: fix refcount leak in nfsd_set_fh_dentry() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b6bc86ce3944b10b9fc181fc00c1a520a20ed965

Vendor Advisories for CVE-2025-40212(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-azure-6.17 (6.17.0-1008.8) @ questing2026-05-21ubuntu
ubuntulinux-tools-oem-6.17 (6.17.0-1011.11) @ noble2026-05-21ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.17.0-14.14) @ questing2026-05-21ubuntu
ubuntulinux-tools-gcp-64k-6.17 (6.17.0-1007.7) @ questing2026-05-21ubuntu
ubuntulinux-tools-oracle-64k-6.17 (6.17.0-1007.7) @ questing2026-05-21ubuntu
linuxKernel @ 6.12.59—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.63-1~bpo12+1 (8 versions)6.12.63-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.17.8-1~bpo13+1 (80 versions)6.17.9-1—

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 5× in last 7d / 25× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 184 total refreshes for this CVE.

  1. 2026-09-20 20:15 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:29 UTCEPSS rescore
  4. 2026-09-16 14:07 UTCEPSS rescore
  5. 2026-09-16 05:14 UTCEPSS rescore
  6. 2026-09-13 16:46 UTCEPSS rescore
  7. 2026-09-12 15:00 UTCEPSS rescore
  8. 2026-09-12 10:10 UTCOSV refresh
  9. 2026-09-11 14:52 UTCEPSS rescore
  10. 2026-09-11 09:35 UTCEPSS rescore
  11. 2026-09-10 09:33 UTCEPSS rescore
  12. 2026-09-08 21:59 UTCEPSS rescore
  13. 2026-09-07 16:00 UTCEPSS rescore
  14. 2026-09-06 13:46 UTCEPSS rescore
  15. 2026-09-04 05:05 UTCEPSS rescore
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:38 UTCEPSS rescore
  19. 2026-08-30 19:16 UTCEPSS rescore
  20. 2026-08-30 01:21 UTCEPSS rescore
  21. 2026-08-28 21:40 UTCEPSS rescore
  22. 2026-08-27 14:24 UTCEPSS rescore
  23. 2026-08-26 14:45 UTCEPSS rescore
  24. 2026-08-25 13:48 UTCEPSS rescore
  25. 2026-08-24 15:03 UTCOSV refresh
Show 75 more
  1. 2026-08-23 00:18 UTCEPSS rescore
  2. 2026-08-21 23:48 UTCEPSS rescore
  3. 2026-08-20 22:54 UTCEPSS rescore
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-19 17:03 UTCEPSS rescore
  6. 2026-08-18 13:47 UTCEPSS rescore
  7. 2026-08-17 13:46 UTCEPSS rescore
  8. 2026-08-16 14:55 UTCEPSS rescore
  9. 2026-08-16 02:13 UTCEPSS rescore
  10. 2026-08-15 01:29 UTCEPSS rescore
  11. 2026-08-13 21:59 UTCEPSS rescore
  12. 2026-08-12 13:50 UTCEPSS rescore
  13. 2026-08-09 13:46 UTCEPSS rescore
  14. 2026-08-08 16:36 UTCEPSS rescore
  15. 2026-08-08 09:34 UTCEG score recompute
  16. 2026-08-08 09:34 UTCVendor advisory
  17. 2026-08-08 09:34 UTCGHSA enrichment
  18. 2026-08-07 16:26 UTCEPSS rescore
  19. 2026-08-06 13:46 UTCEPSS rescore
  20. 2026-08-05 12:51 UTCEG score recompute
  21. 2026-08-05 12:51 UTCVendor advisory
  22. 2026-08-05 12:51 UTCGHSA enrichment
  23. 2026-08-04 15:09 UTCEPSS rescore
  24. 2026-08-04 10:37 UTCEPSS rescore
  25. 2026-08-02 02:26 UTCEPSS rescore
  26. 2026-08-01 04:15 UTCEPSS rescore
  27. 2026-07-30 16:27 UTCEPSS rescore
  28. 2026-07-30 06:26 UTCEG score recompute▲ 9.80
  29. 2026-07-30 06:25 UTCGHSA enrichment
  30. 2026-07-30 06:18 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  31. 2026-07-30 01:29 UTCEPSS rescore
  32. 2026-07-28 15:35 UTCEPSS rescore
  33. 2026-07-27 06:39 UTCOSV refresh
  34. 2026-07-26 14:54 UTCEPSS rescore
  35. 2026-07-25 14:17 UTCEPSS rescore
  36. 2026-07-25 14:17 UTCEPSS rescore
  37. 2026-07-24 14:17 UTCEPSS rescore
  38. 2026-07-23 02:55 UTCEG score recompute
  39. 2026-07-22 14:07 UTCEPSS rescore
  40. 2026-07-22 14:07 UTCEPSS rescore
  41. 2026-07-21 15:24 UTCEPSS rescore
  42. 2026-07-20 17:07 UTCEPSS rescore
  43. 2026-07-19 14:30 UTCEPSS rescore
  44. 2026-07-19 14:30 UTCEPSS rescore
  45. 2026-07-19 02:28 UTCEPSS rescore
  46. 2026-07-19 02:28 UTCEPSS rescore
  47. 2026-07-18 10:04 UTCEPSS rescore
  48. 2026-07-18 10:04 UTCEPSS rescore
  49. 2026-07-16 17:02 UTCEPSS rescore
  50. 2026-07-15 16:57 UTCEPSS rescore
  51. 2026-07-15 16:57 UTCEPSS rescore
  52. 2026-07-15 01:59 UTCEPSS rescore
  53. 2026-07-15 01:59 UTCEPSS rescore
  54. 2026-07-13 22:29 UTCEPSS rescore
  55. 2026-07-13 22:29 UTCEPSS rescore
  56. 2026-07-13 06:12 UTCEPSS rescore
  57. 2026-07-12 05:46 UTCEPSS rescore
  58. 2026-07-11 08:27 UTCEPSS rescore
  59. 2026-07-11 08:27 UTCEPSS rescore
  60. 2026-07-10 00:47 UTCOSV refresh
  61. 2026-07-09 19:09 UTCEPSS rescore
  62. 2026-07-09 19:09 UTCEPSS rescore
  63. 2026-07-07 13:45 UTCEPSS rescore
  64. 2026-07-06 16:27 UTCEPSS rescore
  65. 2026-07-06 16:27 UTCEPSS rescore
  66. 2026-07-06 02:23 UTCEPSS rescore
  67. 2026-07-05 02:30 UTCEPSS rescore
  68. 2026-07-04 06:30 UTCEPSS rescore
  69. 2026-07-01 15:06 UTCEPSS rescore
  70. 2026-07-01 15:06 UTCEPSS rescore
  71. 2026-06-30 23:22 UTCEPSS rescore
  72. 2026-06-30 23:22 UTCEPSS rescore
  73. 2026-06-29 14:06 UTCEPSS rescore
  74. 2026-06-29 14:06 UTCEPSS rescore
  75. 2026-06-28 14:07 UTCEPSS rescore

Related CVEs(same product + same vendor)

Frequently asked(5)

What is CVE-2025-40212?
CVE-2025-40212 is a critical vulnerability published on November 24, 2025. In the Linux kernel, the following vulnerability has been resolved: nfsd: fix refcount leak in nfsdsetfh_dentry() nfsd exports a "pseudo root filesystem" which is used by NFSv4 to find the various exported filesystems using LOOKUP requests from a known root filehandle. NFSv3 uses the MOUNT protocol…
When was CVE-2025-40212 disclosed?
CVE-2025-40212 was first published in the National Vulnerability Database on November 24, 2025, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-40212 actively exploited?
CVE-2025-40212 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 65.9% of all scored CVEs.
What is the CVSS score of CVE-2025-40212?
CVE-2025-40212 has a CVSS v4.0 base score of 9.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2025-40212?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-40212, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-40212

Explore →

Is Your Infrastructure Affected by CVE-2025-40212?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs