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Vulnerabilities

Vulnerability · CVE-2025-39764

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

Published Sep 11, 2025 · catalog updated Oct 19, 2026 · Linux Linux

Check if you run it

No confirmed exploitation is on record for CVE-2025-39764. EPSS is 0.17%. Act only if a listed version of Linux Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.17%
Remediation
Version ranges on file
Affected products
cpe linux/linux kernel · vendor Linux Linux cf6994c2b9812a9f02b99e89df411ffc5db9c779 <9e5021a906532ca16e2aac69c0607711e1c70b1f

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernel6.17
  • vendor Linux Linux cf6994c2b9812a9f02b99e89df411ffc5db9c779 <9e5021a906532ca16e2aac69c0607711e1c70b1fcf6994c2b9812a9f02b99e89df411ffc5db9c779 <9e5021a906532ca16e2aac69c0607711e1c70b1f

How to fix CVE-2025-39764

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-39764. EPSS is 0.17%. Act only if a listed version of Linux Linux is installed.

Which versions are affected?

Compare what you have installed with linux/linux kernel 6.17; Linux Linux cf6994c2b9812a9f02b99e89df411ffc5db9c779 <9e5021a906532ca16e2aac69c0607711e1c70b1f cf6994c2b9812a9f02b99e89df411ffc5db9c779 <9e5021a906532ca16e2aac69c0607711e1c70b1f. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.17%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 11, 2025 · NIST NVD

    Detected

    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 (!refcoun

  2. Oct 15, 2026 · NIST NVD

    Updated

    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 (!refcoun

  3. Oct 19, 2026 · NIST NVD

    Updated

    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 (!refcoun

Sources

  • CVE.orgVulnerability recordCVE-2025-39764

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-39764

    30-day exploitation probability 0.2%

    first.org
  • EUVDVulnerability recordEUVD-2025-28948

    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

    euvd.enisa.europa.eu
  • NIST NVDVulnerability recordCVE-2025-39764

    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 hin

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.