{"id":7071,"date":"2026-09-04T18:49:24","date_gmt":"2026-09-04T10:49:24","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-72418"},"modified":"2026-09-04T18:49:24","modified_gmt":"2026-09-04T10:49:24","slug":"cve-2026-72418","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-72418","title":{"rendered":"CVE-2026-72418 [HIGH] &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conncou"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>netfilter: nf_conncount: prevent connlimit drops for early confirmed ct<\/p>\n<p>Commit 69894e5b4c5e (&#8220;netfilter: nft_connlimit: update the count if add<br \/>\nwas skipped&#8221;) introduced a regression where packets for valid<br \/>\nconnections are dropped when using connlimit for soft-limiting<br \/>\nscenarios.<\/p>\n<p>The issue occurs when a new connection reuses a socket currently in<br \/>\nthe TIME_WAIT state. In this scenario, the connection tracking entry<br \/>\nis evaluated as already confirmed. Previously, __nf_conncount_add()<br \/>\nassumed that if a connection was confirmed and did not originate from<br \/>\nthe loopback interface, it should skip the addition and return -EEXIST.<\/p>\n<p>Skipping the addition triggers a garbage collection run that cleans up<br \/>\nthe TIME_WAIT connection. Consequently, the active connection count<br \/>\ndrops to 0, which xt_connlimit mishandles, leading to the false rejection<br \/>\nof the perfectly valid new connection.<\/p>\n<p>Fix this by replacing the interface check with protocol-agnostic state<br \/>\nchecks. We now skip the tree insertion and preserve the lockless garbage<br \/>\ncollection optimization only if the connection is IPS_ASSURED. This<br \/>\nallows early-confirmed setup packets (such as reused TIME_WAIT sockets<br \/>\nor locally generated SYN-ACKs) to be properly evaluated and counted<br \/>\nwithout falsely dropping. The goto check_connections path is maintained<br \/>\nto ensure these setup packets are deduplicated correctly.<\/p>\n<p>This has been tested with slowhttptest and HTTP server configured<br \/>\nlocally to ensure we are not breaking soft-limiting scenarios for local<br \/>\nor external connections. In addition, it was tested with a OVS zone<br \/>\nlimit too.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>netfilter: nf_conncount: prevent connlimit drops for early confirmed ct<\/p>\n<p>Commit 69894e5b4c5e (&#8220;netfilter: nft_connlimit: update the<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-7071","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/7071","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7071"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7071"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7071"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}