{"id":"CVE-2026-74715","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix netns reference imbalance in conntrack kfuncs\n\nThe opts argument of the BPF conntrack kfuncs can point to a shared\nmap value","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix netns reference imbalance in conntrack kfuncs\n\nThe opts argument of the BPF conntrack kfuncs can point to a shared\nmap value.  __bpf_nf_ct_lookup() and __bpf_n…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= aed8ee7feb44b6537af1e0b4f03365d42928be38 < 4af94462c0ca2187a02a1a6641020ae888c74d5c","Linux >= aed8ee7feb44b6537af1e0b4f03365d42928be38 < e5e060eb63d10b41ab60fd955649479d99b38210","Linux >= aed8ee7feb44b6537af1e0b4f03365d42928be38 < fdeba03fea78407a8c52faa99177c9f7f29f90eb","Linux 6.0"],"published":"2026-08-22","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:48.573","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74715","references":[{"url":"https://git.kernel.org/stable/c/4af94462c0ca2187a02a1a6641020ae888c74d5c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e5e060eb63d10b41ab60fd955649479d99b38210","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fdeba03fea78407a8c52faa99177c9f7f29f90eb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fb22bedf0c4f4f05bfa6e4a7ec0fd97bbdff9ce8"},{"url":"https://git.kernel.org/stable/c/41731d4290400cb898f15f049ae4018d45415e69"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74715.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-74715"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2521369"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74715"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74715"},{"url":"https://kernelcve.org/list/?q=CVE-2026-74715"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082238-CVE-2026-74715-a8ca@gregkh/T"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00129,"epssPercentile":0.02481,"ingestedAt":"2026-10-14T13:30:58.546Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:15:29.946901Z"},"cwe":["CWE-416"],"scores":{"nvd":7.8,"vendor":4.7},"slug":"CVE-2026-74715","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix netns reference imbalance in conntrack kfuncs\n\nThe opts argument of the BPF conntrack kfuncs can point to a shared\nmap value.  __bpf_nf_ct_lookup() and __bpf_nf_ct_alloc_entry() read\nopts->netns_id separately when acquiring and releasing the network\nnamespace reference.\n\nThe reference imbalance can occur as follows:\n\n  CPU 0                                  CPU 1\n  read opts->netns_id (-1)\n  skip get_net_ns_by_id()\n                                         write opts->netns_id (id)\n  read opts->netns_id (id)\n  put_net(net) /* no matching get */\n\nThe reverse transition leaks the reference.  Repeating the unmatched put\ncan destroy a live namespace and crash later users.\n\nThe kernel reported:\n\n  Oops: general protection fault, probably for non-canonical address\n  KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]\n  RIP: 0010:bpf_prog_test_run_xdp+0x52c/0x1700\n  Call Trace:\n   __sys_bpf+0x1662/0x50c0\n   __x64_sys_bpf+0x73/0xb0\n   do_syscall_64+0xf9/0x540\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n  Kernel panic - not syncing: Fatal exception\n\nSnapshot every input field of opts with READ_ONCE() before validating or\nusing it.  The netns_id snapshot keeps the namespace get/put pair\nbalanced, while the other snapshots keep the remaining options from\nchanging partway through an invocation.  The individual reads can still\nobserve an inconsistent combination during a concurrent update, but each\nselected field value remains stable for that invocation.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74715.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}