{"id":"CVE-2025-39764","title":"netfilter: ctnetlink: remove refcounting in expectation dumpers","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: remove refcounting in expectation dumpers\n\nSame pattern as previous patch: do not keep the expectation object\nalive via refcount, only store a coo…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < b05500444b8eb97644efdd180839a04a706be97c","Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < bada48ad5b0590e318d0f79636ff62a2ef9f4955","Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 64b7684042246e3238464c66894e30ba30c7e851","Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 9e5021a906532ca16e2aac69c0607711e1c70b1f","Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 078d33c95bf534d37aa04269d1ae6158e20082d5","Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < a4d634ded4d3d400f115d84f654f316f249531c9","Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 1492e3dcb2be3aa46d1963da96aa9593e4e4db5a","Linux 2.6.23"],"published":"2025-09-11","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:42:13.716Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-39764","references":[{"url":"https://git.kernel.org/stable/c/b05500444b8eb97644efdd180839a04a706be97c"},{"url":"https://git.kernel.org/stable/c/bada48ad5b0590e318d0f79636ff62a2ef9f4955"},{"url":"https://git.kernel.org/stable/c/64b7684042246e3238464c66894e30ba30c7e851"},{"url":"https://git.kernel.org/stable/c/9e5021a906532ca16e2aac69c0607711e1c70b1f"},{"url":"https://git.kernel.org/stable/c/078d33c95bf534d37aa04269d1ae6158e20082d5"},{"url":"https://git.kernel.org/stable/c/a4d634ded4d3d400f115d84f654f316f249531c9"},{"url":"https://git.kernel.org/stable/c/1492e3dcb2be3aa46d1963da96aa9593e4e4db5a"}],"tags":["cve.org"],"epss":0.00165,"epssPercentile":0.06156,"ingestedAt":"2026-09-08T15:33:26.997Z","slug":"CVE-2025-39764","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: remove refcounting in expectation dumpers\n\nSame pattern as previous patch: do not keep the expectation object\nalive via refcount, only store a cookie value and then use that\nas the skip hint for dump resumption.\n\nAFAICS this has the same issue as the one resolved in the conntrack\ndumper, when we do\n  if (!refcount_inc_not_zero(&exp->use))\n\nto increment the refcount, there is a chance that exp == last, which\ncauses a double-increment of the refcount and subsequent memory leak.\n\n## Affected\n\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < b05500444b8eb97644efdd180839a04a706be97c`\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < bada48ad5b0590e318d0f79636ff62a2ef9f4955`\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 64b7684042246e3238464c66894e30ba30c7e851`\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 9e5021a906532ca16e2aac69c0607711e1c70b1f`\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 078d33c95bf534d37aa04269d1ae6158e20082d5`\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < a4d634ded4d3d400f115d84f654f316f249531c9`\n- `Linux >= cf6994c2b9812a9f02b99e89df411ffc5db9c779 < 1492e3dcb2be3aa46d1963da96aa9593e4e4db5a`\n- `Linux 2.6.23`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}