{"id":"CVE-2026-74282","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74282","summary":"tipc: prevent snt_unacked underflow on CONN_ACK","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: prevent snt_unacked underflow on CONN_ACK\n\ntipc_sk_conn_proto_rcv() subtracts the peer-supplied connection ack count\nfrom the unsigned 16-bit send counter snt_unacked without checking that it\ndoes not exceed the number of messages actually outstanding:\n\n\ttsk->snt_unacked -= msg_conn_ack(hdr);\n\nmsg_conn_ack() is read straight from a received CONN_MANAGER/CONN_ACK\nmessage. If the ack count is larger than snt_unacked, the subtraction\nwraps to a near-maximum value, leaving tsk_conn_cong() permanently true\nand starving the connection of further transmits.\n\nValidate the ACK count at the start of the CONN_ACK block and drop the\nmessage if it acknowledges more messages than are outstanding. A peer (or,\nfor a local connection, the connected peer socket) can otherwise wedge a\nTIPC connection's send side by sending an oversized connection ack.","published":"2026-08-15T05:57:52.048Z","modified":"2026-08-18T03:56:56.673293054Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"5.10.261"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1e2c956745777e6ffdee7f30da5935741c03ee1e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3388145d258cf2c4c98278e3987296007d30672e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3cfa3d8e0dc167850edeb5bf5a07757db83fd54e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/47ed873e4ceda34098bd46d8e96b4bb13cad3a04"},{"type":"WEB","url":"https://git.kernel.org/stable/c/67e55b054bf8025658dc0e255057f2a6236416bd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/96f91b8ae1a489b3eca137e7acf42cf985fb8939"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab3e10b44ba5411779aac7afd2477917dd77750f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b44bebdd32c9ff66ee2aebfc317ced44bedd9335"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74282.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74282"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:56.673293054Z"}}