CVE-2025-40320

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2025-12-08. 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:

smb: client: fix potential cfid UAF in smb2_query_info_compound

When smb2_query_info_compound() retries, a previously allocated cfid may have been freed in the first attempt. Because cfid wasn't reset on replay, later cleanup could act on a stale pointer, leading to a potential use-after-free.

Reinitialize cfid to NULL under the replay label.

Example trace (trimmed):

refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 11224 at ../lib/refcount.c:28 refcount_warn_saturate+0x9c/0x110 [...] RIP: 0010:refcount_warn_saturate+0x9c/0x110 [...] Call Trace: smb2_query_info_compound+0x29c/0x5c0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? step_into+0x10d/0x690 ? __legitimize_path+0x28/0x60 smb2_queryfs+0x6a/0xf0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] smb311_queryfs+0x12d/0x140 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? kmem_cache_alloc+0x18a/0x340 ? getname_flags+0x46/0x1e0 cifs_statfs+0x9f/0x2b0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] statfs_by_dentry+0x67/0x90 vfs_statfs+0x16/0xd0 user_statfs+0x54/0xa0 __do_sys_statfs+0x20/0x50 do_syscall_64+0x58/0x80

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

December 8, 2025

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Aug 26, 2026
No patch confirmed yet.
generic

smb: client: fix potential cfid UAF in smb2_query_info_compound - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5c76f9961c170552c1d07c830b5e145475151600
generic

smb: client: fix potential cfid UAF in smb2_query_info_compound - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b556c278d43f4707a9073ca74d55581b4f279806
generic

smb: client: fix potential cfid UAF in smb2_query_info_compound - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/327f89c21601ebb7889f8c97754b76f08ce95a0c
generic

smb: client: fix potential cfid UAF in smb2_query_info_compound - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/939c4e33005e2a56ea8fcedddf0da92df864bd3b

Vendor Advisories for CVE-2025-40320(2)

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

Patch Availability(17)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-xilinx-zynqmp (6.8.0.1029.30) @ noble2026-05-21ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2040.41) @ noble2026-05-21ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1052.55+fips1) @ noble2026-05-21ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1049.52.1) @ noble2026-05-21ubuntu
ubuntulinux-tools-realtime-6.8.1 (6.8.1-1045.46) @ noble2026-05-21ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1051.57) @ noble2026-05-21ubuntu
ubuntulinux-tools-aws-edge (6.8.0-1050.53~22.04.1) @ jammy2026-05-21ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1052.58+fips1) @ noble2026-05-21ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.17.0-14.14) @ questing2026-05-21ubuntu
ubuntulinux-virtual-6.8 (6.8.0-106.106) @ noble2026-05-21ubuntu
ubuntulinux-tools-oem-6.17 (6.17.0-1011.11) @ noble2026-05-21ubuntu
ubuntulinux-tools-oracle-64k-6.17 (6.17.0-1007.7) @ 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-azure-edge (6.8.0-1051.57~22.04.1) @ jammy2026-05-21ubuntu
redhatkernel-0:6.12.0-211.7.1.el10_22026-05-19redhat
linuxKernel @ 6.6.117—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 (76 versions)6.17.8-1—

Additional Vendor Advisories

(15)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 7× in last 7d / 34× 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 167 total refreshes for this CVE.

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

Related CVEs(same product + same vendor)

Frequently asked(5)

What is CVE-2025-40320?
CVE-2025-40320 is a critical vulnerability published on December 8, 2025. In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential cfid UAF in smb2queryinfo_compound When smb2queryinfo_compound() retries, a previously allocated cfid may have been freed in the first attempt. Because cfid wasn't reset on replay, later cleanup could act…
When was CVE-2025-40320 disclosed?
CVE-2025-40320 was first published in the National Vulnerability Database on December 8, 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-2025-40320 actively exploited?
CVE-2025-40320 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 66.1% of all scored CVEs.
What is the CVSS score of CVE-2025-40320?
CVE-2025-40320 has a CVSS v4.0 base score of 9.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2025-40320?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-40320, 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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