{"id":5332,"date":"2026-09-04T18:47:45","date_gmt":"2026-09-04T10:47:45","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-68118"},"modified":"2026-09-04T18:47:45","modified_gmt":"2026-09-04T10:47:45","slug":"cve-2026-68118","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-68118","title":{"rendered":"CVE-2026-68118 [HIGH] &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: challenge ACK fo"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>tcp: challenge ACK for non-exact RST in SYN-RECEIVED<\/p>\n<p>The SYN-RECEIVED request-socket path in tcp_check_req() accepts an<br \/>\nin-window RST without requiring SEG.SEQ to exactly match RCV.NXT.  A<br \/>\nnon-exact RST therefore removes the request instead of eliciting a<br \/>\nchallenge ACK.<\/p>\n<p>RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in<br \/>\nSYN-RECEIVED: an exact RST resets the connection, while a non-exact<br \/>\nin-window RST must trigger a challenge ACK and be dropped.<\/p>\n<p>Apply that check before the ACK-field validation, following the RFC<br \/>\nsequence-number, RST, then ACK processing order.  Factor the per-netns<br \/>\nchallenge ACK quota out of tcp_send_challenge_ack() so request sockets<br \/>\ncan share it.  Use the request socket&#8217;s send_ack() callback and its own<br \/>\nout-of-window ACK timestamp to send and rate-limit the response.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>tcp: challenge ACK for non-exact RST in SYN-RECEIVED<\/p>\n<p>The SYN-RECEIVED request-socket path in tcp_check_req() accepts an<br \/>\nin-window <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5332","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5332","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=5332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}