{"id":"CVE-2026-74496","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-74496","generatedAt":"2026-10-28T08:10:05.655Z","title":"In the Linux kernel, the following vulnerability has been resolved: fou: Fix use-after-free in fou_create() fou_create() publishes struct fou through sk_user_data before adding the new FOU port to the per-netns list.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfou: Fix use-after-free in fou_create()\n\nfou_create() publishes struct fou through sk_user_data before adding the\nnew FOU port to the per-netns list.  If fou_add_to_port_list() fails,\nthe error path frees fou while it is still reachable through\nsk_user_data.  A concurrent receive can then dereference the freed\nobject in fou_from_sock().\n\nThis ordering issue was previously noted in the linked discussion.\n\nThe failure is reachable when local port 0 is requested.  Each socket\nbinds to a different ephemeral port, but fou_cfg_cmp() compares the\nrequested port 0 and reports -EALREADY once an entry already exists.\n\nRelease the tunnel socket before freeing fou so sk_user_data is cleared\nfirst, and defer reclamation with kfree_rcu() to protect concurrent RCU\nreaders.  This matches the lifetime handling in fou_release().","published":"2026-08-15T13:17:55.000Z","lastModified":"2026-10-16T20:17:33.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":[],"affected":[],"epss":{"score":0.00126,"percentile":0.0224,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/0ee628a58d83e571f36ec9f07624d6845e420c50","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/58835985c035a8333742f829ad7e0889a082f9d3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9042867d4701728f0c6527215b11471759904d8f","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/99f4d3120b244f92e5df787152041296a2860cb5","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a28d8903bfe76089ea4bbdbff9976965f9ef8107","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a6fca682cfa2041e31aa72cc397c4a1406eb7468","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b14361aca6350ff7907b0e9903c7b94dc7d5d4a0","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b3f9c3e60aa25453774f899d25b5e61dd0bec1d5","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74496","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}