{"apiVersion":"1.0","identifier":"CVE-2026-99201","description":"In the Linux kernel, the following vulnerability has been resolved: netlink: avoid hashing the network namespace pointer The netlink rhashtable key includes a raw struct net pointer and a user-controlled port ID. Both /proc/net/netlink and socket diagnostics expose the table-s bucket order. By binding and rebinding chosen NETLINK_USERSOCK port IDs, an unprivileged reader can distinguish equal buckets and recover the low bits of the Jenkins hash. Its 32-bit seed and the limited set of kernel-image slides can then be searched offline to recover the address of init_net. Use the namespace-s unique, non-address net_cookie in the comparison key instead. It is assigned before the per-net initializers run and remains unchanged for the namespace-s lifetime. The lookup key and object hash are still built by netlink_compare_arg_init(), keeping lookup, insertion, removal and rehashing consistent while preserving namespace separation. Neither public table walker needs to change. Reading the socket-s namespace cookie in netlink_compare() is safe under RCU, including during namespace teardown. netlink_release() removes the socket from the hash table and defers its final put with call_rcu(). cleanup_net() runs the per-net exit methods and waits for outstanding RCU callbacks with rcu_barrier() before freeing namespace storage. Unlike ns.ns_id, net_cookie is also available and initialized during setup_net() in older stable kernels, making the change straightforward to backport to v5.15 and later.","publishedAt":"2026-10-28T11:17:41","lastModifiedAt":"2026-10-30T13:21:52","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-99201","cvssScore":null,"cvssVector":null,"epssProbability":0.00171,"riskScore":null,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-99201","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-99201","en":"https://www.redsauce.net/en/cves/CVE-2026-99201","fr":"https://www.redsauce.net/fr/cves/CVE-2026-99201","pt":"https://www.redsauce.net/pt/cves/CVE-2026-99201","de":"https://www.redsauce.net/de/cves/CVE-2026-99201","sk":"https://www.redsauce.net/sk/cves/CVE-2026-99201","el":"https://www.redsauce.net/el/cves/CVE-2026-99201"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-99201"}}