{"cve":"CVE-2023-53635","nvd":{"published":"2025-10-07T16:15:46.643","modified":"2026-10-15T22:17:44.927","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: fix wrong ct->timeout value\n\n(struct nf_conn)->timeout is an interval before the conntrack\nconfirmed.  After confirmed, it becomes a timestamp.\n\nIt is observed that timeout of an unconfirmed conntrack:\n- Set by calling ctnetlink_change_timeout(). As a result,\n  `nfct_time_stamp` was wrongly added to `ct->timeout` twice.\n- Get by calling ctnetlink_dump_timeout(). As a result,\n  `nfct_time_stamp` was wrongly subtracted.\n\nCall Trace:\n <TASK>\n dump_stack_lvl\n ctnetlink_dump_timeout\n __ctnetlink_glue_build\n ctnetlink_glue_build\n __nfqnl_enqueue_packet\n nf_queue\n nf_hook_slow\n ip_mc_output\n ? __pfx_ip_finish_output\n ip_send_skb\n ? __pfx_dst_output\n udp_send_skb\n udp_sendmsg\n ? __pfx_ip_generic_getfrag\n sock_sendmsg\n\nSeparate the 2 cases in:\n- Setting `ct->timeout` in __nf_ct_set_timeout().\n- Getting `ct->timeout` in ctnetlink_dump_timeout().\n\nPablo appends:\n\nUpdate ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is\nset on, otherwise conntrack creation via ctnetlink breaks.\n\nNote that the problem described in this patch occurs since the\nintroduction of the nfnetlink_queue conntrack support, select a\nsufficiently old Fixes: tag for -stable kernel to pick up this fix.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/73db1b8f2bb6725b7391e85aab41fdf592b3c0c1","https://git.kernel.org/stable/c/80c5ba0078e20d926d11d0778f9a43902664ebf0","https://git.kernel.org/stable/c/f612ae1ab4793701caf39386fb3b7f4b3ef44e48","https://git.kernel.org/stable/c/ff5e4ac8dd7be7f1faba955c5779a68571eeb0f8"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2023-53635","score":0.00425,"percentile":0.36477,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}