CVE-2025-37899

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2025-05-20. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this weekElevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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

ksmbd: fix use-after-free in session logoff

The sess->user object can currently be in use by another thread, for example if another connection has sent a session setup request to bind to the session being free'd. The handler for that connection could be in the smb2_sess_setup function which makes use of sess->user.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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
Severity78% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
57%
KEV
Not listed

Published

May 20, 2025

Last Modified

August 5, 2026

Advisory Details (7)

Auto-updated Jul 30, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

How I used o3 to find CVE-2025-37899, a remote zeroday vulnerability in the Linux kernel’s SMB implementation – Sean Heelan's Blog

https://sean.heelan.io/2025/05/22/how-i-used-o3-to-find-cve-2025-37899-a-remote-zeroday-vulnerability-in-the-linux-kernels-smb-implementation/
generic🟡 PoC Available

I used o3 to find a remote zeroday in the Linux SMB implementation | Hacker News

https://news.ycombinator.com/item?id=44081338
generic

ksmbd: fix use-after-free in session logoff - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d5ec1d79509b3ee01de02c236f096bc050221b7f
generic

ksmbd: fix use-after-free in session logoff - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/931dc8a3670f71c45c0b1379ea4e92dafbda1aca
generic

ksmbd: fix use-after-free in session logoff - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/70ad6455139e26e85f48f95d0e21f351c1909342
generic

ksmbd: fix use-after-free in session logoff - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2fc9feff45d92a92cd5f96487655d5be23fb7e2b
generic

ksmbd: fix use-after-free in session logoff - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/02d16046cd11a5c037b28c12ffb818c56dd3ef43

Vendor Advisories for CVE-2025-37899(1)

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

Patch Availability(18)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-24.04-edge (6.14.0-24.24) @ plucky2026-05-30ubuntu
ubuntulinux-tools-oem-6.14 (6.14.0-1007.7) @ noble2026-05-30ubuntu
ubuntulinux-tools-aws-64k-6.14 (6.14.0-1009.9) @ plucky2026-05-30ubuntu
ubuntulinux-tools-aws-edge (6.14.0-1009.9~24.04.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-64k-6.14 (6.14.0-1009.9) @ plucky2026-05-30ubuntu
ubuntulinux-tools-azure-6.14 (6.14.0-1010.10) @ plucky2026-05-30ubuntu
ubuntulinux-virtual-6.8 (6.8.0-101.101) @ noble2026-05-30ubuntu
ubuntulinux-tools-gke-64k-6.8 (6.8.0-1044.49) @ noble2026-05-30ubuntu
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2038.39) @ noble2026-05-30ubuntu
ubuntulinux-tools-realtime-6.8.1 (6.8.1-1042.43) @ noble2026-05-30ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1048.51+fips1) @ noble2026-05-30ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1024.25) @ noble2026-05-30ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1047.50.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1047.53+fips1) @ noble2026-05-30ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1047.50+fips1) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1051.57) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-edge (6.8.0-1051.57~22.04.1) @ jammy2026-05-30ubuntu
linuxKernel @ 6.1.159—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.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(17)

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 9× in last 7d / 45× 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 110 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCSeanHeelan/o3_finds_cve-2025-37899
    First seen May 22, 2025

    Artefacts for blog post on finding CVE-2025-37899 with o3

    Open source ↗

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2025-37899?
CVE-2025-37899 is a high vulnerability published on May 20, 2025. In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in session logoff The sess->user object can currently be in use by another thread, for example if another connection has sent a session setup request to bind to the session being free'd. The handler for…
When was CVE-2025-37899 disclosed?
CVE-2025-37899 was first published in the National Vulnerability Database on May 20, 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-2025-37899 actively exploited?
CVE-2025-37899 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 42.8% of all scored CVEs.
What is the CVSS score of CVE-2025-37899?
CVE-2025-37899 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2025-37899?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-37899, 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

Explore the affected products and dependency analysis for CVE-2025-37899

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