CVE-2025-39764

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2025-09-11. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

netfilter: ctnetlink: remove refcounting in expectation dumpers

Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump resumption.

AFAICS this has the same issue as the one resolved in the conntrack dumper, when we do if (!refcount_inc_not_zero(&exp->use))

to increment the refcount, there is a chance that exp == last, which causes a double-increment of the refcount and subsequent memory leak.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity55% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
5%
KEV
Not listed

Published

September 11, 2025

Last Modified

July 14, 2026

Advisory Details (9)

Auto-updated Jul 19, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

SSA-082556

https://cert-portal.siemens.com/productcert/html/ssa-082556.html
generic

SSA-019113

https://cert-portal.siemens.com/productcert/html/ssa-019113.html
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bada48ad5b0590e318d0f79636ff62a2ef9f4955
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b05500444b8eb97644efdd180839a04a706be97c
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a4d634ded4d3d400f115d84f654f316f249531c9
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9e5021a906532ca16e2aac69c0607711e1c70b1f
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/64b7684042246e3238464c66894e30ba30c7e851
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1492e3dcb2be3aa46d1963da96aa9593e4e4db5a
generic

netfilter: ctnetlink: remove refcounting in expectation dumpers - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/078d33c95bf534d37aa04269d1ae6158e20082d5

Vendor Advisories for CVE-2025-39764(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.10.253—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.

Data Freshness Timeline

(refreshed 6× in last 7d / 40× 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 128 total refreshes for this CVE.

  1. 2026-08-01 04:15 UTCEPSS rescore
  2. 2026-07-30 16:27 UTCEPSS rescore
  3. 2026-07-30 01:29 UTCEPSS rescore
  4. 2026-07-28 15:35 UTCEPSS rescore
  5. 2026-07-27 12:09 UTCOSV refresh
  6. 2026-07-26 14:54 UTCEPSS rescore
  7. 2026-07-25 14:17 UTCEPSS rescore
  8. 2026-07-25 14:17 UTCEPSS rescore
  9. 2026-07-24 14:17 UTCEPSS rescore
  10. 2026-07-23 02:55 UTCEG score recompute
  11. 2026-07-22 14:07 UTCEPSS rescore
  12. 2026-07-22 14:07 UTCEPSS rescore
  13. 2026-07-21 15:24 UTCEPSS rescore
  14. 2026-07-20 17:07 UTCEPSS rescore
  15. 2026-07-19 14:30 UTCEPSS rescore
  16. 2026-07-19 14:30 UTCEPSS rescore
  17. 2026-07-19 02:28 UTCEPSS rescore
  18. 2026-07-19 02:28 UTCEPSS rescore
  19. 2026-07-18 10:04 UTCEPSS rescore
  20. 2026-07-18 10:04 UTCEPSS rescore
  21. 2026-07-16 17:02 UTCEPSS rescore
  22. 2026-07-15 16:57 UTCEPSS rescore
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-15 01:59 UTCEPSS rescore
  25. 2026-07-15 01:59 UTCEPSS rescore
Show 75 more
  1. 2026-07-14 13:19 UTCNVD updateCVSS v3 → 5.5 · severity → MEDIUM
  2. 2026-07-14 13:11 UTCMITRE cvelistV5
  3. 2026-07-13 22:29 UTCEPSS rescore
  4. 2026-07-13 22:29 UTCEPSS rescore
  5. 2026-07-13 06:12 UTCEPSS rescore
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-10 06:53 UTCOSV refresh
  8. 2026-07-09 19:09 UTCEPSS rescore
  9. 2026-07-09 19:09 UTCEPSS rescore
  10. 2026-07-07 13:45 UTCEPSS rescore
  11. 2026-07-06 16:27 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 02:23 UTCEPSS rescore
  14. 2026-07-05 02:30 UTCEPSS rescore
  15. 2026-07-04 06:30 UTCEPSS rescore
  16. 2026-06-30 23:22 UTCEPSS rescore
  17. 2026-06-30 23:22 UTCEPSS rescore
  18. 2026-06-29 14:06 UTCEPSS rescore
  19. 2026-06-29 14:06 UTCEPSS rescore
  20. 2026-06-28 14:07 UTCEPSS rescore
  21. 2026-06-28 14:07 UTCEPSS rescore
  22. 2026-06-28 04:55 UTCEPSS rescore
  23. 2026-06-28 04:55 UTCEPSS rescore
  24. 2026-06-27 03:08 UTCEPSS rescore
  25. 2026-06-27 03:08 UTCEPSS rescore
  26. 2026-06-25 13:49 UTCEPSS rescore
  27. 2026-06-25 13:49 UTCEPSS rescore
  28. 2026-06-24 14:04 UTCEPSS rescore
  29. 2026-06-24 14:04 UTCEPSS rescore
  30. 2026-06-23 21:32 UTCEPSS rescore
  31. 2026-06-23 21:32 UTCEPSS rescore
  32. 2026-06-22 14:25 UTCEPSS rescore
  33. 2026-06-22 14:25 UTCEPSS rescore
  34. 2026-06-21 16:42 UTCOSV refresh
  35. 2026-06-21 14:56 UTCEPSS rescore
  36. 2026-06-21 14:56 UTCEPSS rescore
  37. 2026-06-21 01:59 UTCEPSS rescore
  38. 2026-06-21 01:59 UTCEPSS rescore
  39. 2026-06-19 19:25 UTCEPSS rescore
  40. 2026-06-19 19:25 UTCEPSS rescore
  41. 2026-06-18 17:52 UTCEPSS rescore
  42. 2026-06-18 17:52 UTCEPSS rescore
  43. 2026-06-17 17:52 UTCEPSS rescore
  44. 2026-06-16 17:52 UTCEPSS rescore
  45. 2026-06-16 17:52 UTCEPSS rescore
  46. 2026-06-14 23:17 UTCEPSS rescore
  47. 2026-06-13 23:00 UTCEPSS rescore
  48. 2026-06-12 23:11 UTCEPSS rescore
  49. 2026-06-11 14:00 UTCEPSS rescore
  50. 2026-06-10 22:18 UTCEPSS rescore
  51. 2026-06-10 13:22 UTCEPSS rescore
  52. 2026-06-08 14:16 UTCEPSS rescore
  53. 2026-06-08 14:16 UTCEPSS rescore
  54. 2026-06-07 15:24 UTCEPSS rescore
  55. 2026-06-06 13:47 UTCEPSS rescore
  56. 2026-06-06 13:47 UTCEPSS rescore
  57. 2026-06-05 22:46 UTCEPSS rescore
  58. 2026-06-05 22:46 UTCEPSS rescore
  59. 2026-06-05 06:10 UTCEPSS rescore
  60. 2026-06-05 06:10 UTCEPSS rescore
  61. 2026-06-04 13:12 UTCEPSS rescore
  62. 2026-06-04 13:12 UTCEPSS rescore
  63. 2026-06-02 20:12 UTCEPSS rescore
  64. 2026-06-02 15:32 UTCOSV refresh
  65. 2026-06-01 13:51 UTCEPSS rescore
  66. 2026-06-01 13:51 UTCEPSS rescore
  67. 2026-05-31 22:30 UTCEPSS rescore
  68. 2026-05-31 22:30 UTCEPSS rescore
  69. 2026-05-31 00:16 UTCEPSS rescore
  70. 2026-05-29 13:44 UTCEPSS rescore
  71. 2026-05-28 13:44 UTCEPSS rescore
  72. 2026-05-28 13:44 UTCEPSS rescore
  73. 2026-05-28 13:44 UTCEPSS rescore
  74. 2026-05-28 13:44 UTCEPSS rescore
  75. 2026-05-27 13:40 UTCEPSS rescore

Frequently asked(5)

What is CVE-2025-39764?
CVE-2025-39764 is a medium vulnerability published on September 11, 2025. In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: remove refcounting in expectation dumpers Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump…
When was CVE-2025-39764 disclosed?
CVE-2025-39764 was first published in the National Vulnerability Database on September 11, 2025, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-39764 actively exploited?
CVE-2025-39764 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 94.9% of all scored CVEs.
What is the CVSS score of CVE-2025-39764?
CVE-2025-39764 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2025-39764?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-39764, 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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