CVE-2025-40362

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2025-12-16. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

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

ceph: fix multifs mds auth caps issue

The mds auth caps check should also validate the fsname along with the associated caps. Not doing so would result in applying the mds auth caps of one fs on to the other fs in a multifs ceph cluster. The bug causes multiple issues w.r.t user authentication, following is one such example.

Steps to Reproduce (on vstart cluster):

  • Create two file systems in a cluster, say 'fsname1' and 'fsname2'
  • Authorize read only permission to the user 'client.usr' on fs 'fsname1'
$ceph fs authorize fsname1 client.usr / r
  • Authorize read and write permission to the same user 'client.usr' on fs 'fsname2'
$ceph fs authorize fsname2 client.usr / rw
  • Update the keyring
$ceph auth get client.usr >> ./keyring

With above permssions for the user 'client.usr', following is the expectation. a. The 'client.usr' should be able to only read the contents and not allowed to create or delete files on file system 'fsname1'. b. The 'client.usr' should be able to read/write on file system 'fsname2'.

But, with this bug, the 'client.usr' is allowed to read/write on file system 'fsname1'. See below.

  • Mount the file system 'fsname1' with the user 'client.usr'
$sudo bin/mount.ceph [email protected]=/ /kmnt_fsname1_usr/
  • Try creating a file on file system 'fsname1' with user 'client.usr'. This
should fail but passes with this bug. $touch /kmnt_fsname1_usr/file1
  • Mount the file system 'fsname1' with the user 'client.admin' and create a
file. $sudo bin/mount.ceph [email protected]=/ /kmnt_fsname1_admin $echo "data" > /kmnt_fsname1_admin/admin_file1
  • Try removing an existing file on file system 'fsname1' with the user
'client.usr'. This shoudn't succeed but succeeds with the bug. $rm -f /kmnt_fsname1_usr/admin_file1

For more information, please take a look at the corresponding mds/fuse patch and tests added by looking into the tracker mentioned below.

v2: Fix a possible null dereference in doutc v3: Don't store fsname from mdsmap, validate against ceph_mount_options's fsname and use it v4: Code refactor, better warning message and fix possible compiler warning

[ Slava.Dubeyko: "fsname check failed" -> "fsname mismatch" ]

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

December 16, 2025

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Jul 30, 2026
No patch confirmed yet.
generic

ceph: fix multifs mds auth caps issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523
generic

ceph: fix multifs mds auth caps issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/22c73d52a6d05c5a2053385c0d6cd9984732799d
generic

ceph: fix multifs mds auth caps issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/07640d34a781bb2e39020a39137073c03c4aa932

Vendor Advisories for CVE-2025-40362(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-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-azure-6.17 (6.17.0-1008.8) @ questing2026-05-21ubuntu
ubuntulinux-tools-oracle-64k-6.17 (6.17.0-1007.7) @ questing2026-05-21ubuntu
linuxKernel @ 6.12.58—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 (79 versions)6.17.8-1—

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 189 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. 2026-09-14 08:20 UTCOSV refresh
  7. 2026-09-13 16:46 UTCEPSS rescore
  8. 2026-09-12 15:00 UTCEPSS rescore
  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. 2026-08-26 09:43 UTCOSV refresh
  25. 2026-08-25 13:48 UTCEPSS rescore
Show 75 more
  1. 2026-08-21 23:48 UTCEPSS rescore
  2. 2026-08-20 22:54 UTCEPSS rescore
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-18 13:47 UTCEPSS rescore
  6. 2026-08-17 13:46 UTCEPSS rescore
  7. 2026-08-16 14:55 UTCEPSS rescore
  8. 2026-08-16 02:13 UTCEPSS rescore
  9. 2026-08-15 01:29 UTCEPSS rescore
  10. 2026-08-13 21:59 UTCEPSS rescore
  11. 2026-08-12 13:50 UTCEPSS rescore
  12. 2026-08-09 23:41 UTCEG score recompute
  13. 2026-08-09 23:41 UTCVendor advisory
  14. 2026-08-09 23:41 UTCGHSA enrichment
  15. 2026-08-09 13:46 UTCEPSS rescore
  16. 2026-08-08 16:36 UTCEPSS rescore
  17. 2026-08-08 06:26 UTCEG score recompute
  18. 2026-08-08 06:26 UTCVendor advisory
  19. 2026-08-08 06:26 UTCGHSA enrichment
  20. 2026-08-06 13:46 UTCEPSS rescore
  21. 2026-08-06 09:07 UTCEG score recompute
  22. 2026-08-06 09:07 UTCVendor advisory
  23. 2026-08-06 09:07 UTCGHSA enrichment
  24. 2026-08-05 12:49 UTCEG score recompute
  25. 2026-08-05 12:49 UTCVendor advisory
  26. 2026-08-05 12:49 UTCGHSA enrichment
  27. 2026-08-04 15:09 UTCEPSS rescore
  28. 2026-08-03 10:35 UTCEPSS rescore
  29. 2026-08-02 02:26 UTCEPSS rescore
  30. 2026-08-01 04:15 UTCEPSS rescore
  31. 2026-07-30 16:27 UTCEPSS rescore
  32. 2026-07-30 06:48 UTCEG score recompute
  33. 2026-07-30 06:48 UTCGHSA enrichment
  34. 2026-07-30 06:23 UTCEG score recompute▲ 8.80
  35. 2026-07-30 06:23 UTCGHSA enrichment
  36. 2026-07-30 06:18 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
  37. 2026-07-30 01:29 UTCEPSS rescore
  38. 2026-07-28 15:35 UTCEPSS rescore
  39. 2026-07-27 04:39 UTCOSV refresh
  40. 2026-07-26 14:54 UTCEPSS rescore
  41. 2026-07-25 14:17 UTCEPSS rescore
  42. 2026-07-25 14:17 UTCEPSS rescore
  43. 2026-07-24 14:17 UTCEPSS rescore
  44. 2026-07-23 02:55 UTCEG score recompute
  45. 2026-07-22 14:07 UTCEPSS rescore
  46. 2026-07-22 14:07 UTCEPSS rescore
  47. 2026-07-21 15:24 UTCEPSS rescore
  48. 2026-07-20 17:07 UTCEPSS rescore
  49. 2026-07-19 14:30 UTCEPSS rescore
  50. 2026-07-19 14:30 UTCEPSS rescore
  51. 2026-07-19 02:28 UTCEPSS rescore
  52. 2026-07-19 02:28 UTCEPSS rescore
  53. 2026-07-18 10:04 UTCEPSS rescore
  54. 2026-07-18 10:04 UTCEPSS rescore
  55. 2026-07-16 17:02 UTCEPSS rescore
  56. 2026-07-15 16:57 UTCEPSS rescore
  57. 2026-07-15 16:57 UTCEPSS rescore
  58. 2026-07-15 01:59 UTCEPSS rescore
  59. 2026-07-15 01:59 UTCEPSS rescore
  60. 2026-07-13 22:29 UTCEPSS rescore
  61. 2026-07-13 22:29 UTCEPSS rescore
  62. 2026-07-13 06:12 UTCEPSS rescore
  63. 2026-07-12 05:46 UTCEPSS rescore
  64. 2026-07-11 08:27 UTCEPSS rescore
  65. 2026-07-11 08:27 UTCEPSS rescore
  66. 2026-07-09 23:17 UTCOSV refresh
  67. 2026-07-09 19:09 UTCEPSS rescore
  68. 2026-07-09 19:09 UTCEPSS rescore
  69. 2026-07-07 13:45 UTCEPSS rescore
  70. 2026-07-06 16:27 UTCEPSS rescore
  71. 2026-07-06 16:27 UTCEPSS rescore
  72. 2026-07-06 02:23 UTCEPSS rescore
  73. 2026-07-05 02:30 UTCEPSS rescore
  74. 2026-07-04 06:30 UTCEPSS rescore
  75. 2026-07-01 15:06 UTCEPSS rescore

Related CVEs(same product + same vendor)

Frequently asked(5)

What is CVE-2025-40362?
CVE-2025-40362 is a high vulnerability published on December 16, 2025. In the Linux kernel, the following vulnerability has been resolved: ceph: fix multifs mds auth caps issue The mds auth caps check should also validate the fsname along with the associated caps. Not doing so would result in applying the mds auth caps of one fs on to the other fs in a multifs ceph…
When was CVE-2025-40362 disclosed?
CVE-2025-40362 was first published in the National Vulnerability Database on December 16, 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-2025-40362 actively exploited?
CVE-2025-40362 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 94.2% of all scored CVEs.
What is the CVSS score of CVE-2025-40362?
CVE-2025-40362 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2025-40362?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-40362, 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

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