{"id":"CVE-2025-21648","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: clamp maximum hashtable size to INT_MAX\n\nUse INT_MAX as maximum size for the conntrack hashtable","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: clamp maximum hashtable size to INT_MAX\n\nUse INT_MAX as maximum size for the conntrack hashtable. Otherwise, it\nis possible to hit WARN_ON_ONCE in…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.7.1, < 5.10.234","linux_kernel >= 5.11, < 5.15.177","linux_kernel >= 5.16, < 6.1.125","linux_kernel >= 6.2, < 6.6.72","linux_kernel >= 6.7, < 6.12.10","linux_kernel = 4.7","linux_kernel = 6.13"],"patched":["linux_kernel 6.12.10"],"published":"2025-01-19","updated":"2026-07-14","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21648","references":[{"url":"https://git.kernel.org/stable/c/5552b4fd44be3393b930434a7845d8d95a2a3c33","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a965f7f0ea3ae61b9165bed619d5d6da02c75f80","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b1b2353d768f1b80cd7fe045a70adee576b9b338","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d5807dd1328bbc86e059c5de80d1bbee9d58ca3d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f559357d035877b9d0dcd273e0ff83e18e1d46aa","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00219,"epssPercentile":0.12617,"ingestedAt":"2026-07-14T13:36:54.847Z","slug":"CVE-2025-21648","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: clamp maximum hashtable size to INT_MAX\n\nUse INT_MAX as maximum size for the conntrack hashtable. Otherwise, it\nis possible to hit WARN_ON_ONCE in __kvmalloc_node_noprof() when\nresizing hashtable because __GFP_NOWARN is unset. See:\n\n  0708a0afe291 (\"mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls\")\n\nNote: hashtable resize is only possible from init_netns.\n\n## Affected\n\n- `linux_kernel >= 4.7.1, < 5.10.234`\n- `linux_kernel >= 5.11, < 5.15.177`\n- `linux_kernel >= 5.16, < 6.1.125`\n- `linux_kernel >= 6.2, < 6.6.72`\n- `linux_kernel >= 6.7, < 6.12.10`\n- `linux_kernel = 4.7`\n- `linux_kernel = 6.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.12.10`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}