{"id":"CVE-2026-74282","title":"tipc: prevent snt_unacked underflow on CONN_ACK","summary":"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_una…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 3388145d258cf2c4c98278e3987296007d30672e","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 67e55b054bf8025658dc0e255057f2a6236416bd","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 96f91b8ae1a489b3eca137e7acf42cf985fb8939","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 47ed873e4ceda34098bd46d8e96b4bb13cad3a04","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < b44bebdd32c9ff66ee2aebfc317ced44bedd9335","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 3cfa3d8e0dc167850edeb5bf5a07757db83fd54e","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 1e2c956745777e6ffdee7f30da5935741c03ee1e","Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < ab3e10b44ba5411779aac7afd2477917dd77750f","Linux 4.7"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T18:52:07.516475Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:55:29.895Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74282","references":[{"url":"https://git.kernel.org/stable/c/3388145d258cf2c4c98278e3987296007d30672e"},{"url":"https://git.kernel.org/stable/c/67e55b054bf8025658dc0e255057f2a6236416bd"},{"url":"https://git.kernel.org/stable/c/96f91b8ae1a489b3eca137e7acf42cf985fb8939"},{"url":"https://git.kernel.org/stable/c/47ed873e4ceda34098bd46d8e96b4bb13cad3a04"},{"url":"https://git.kernel.org/stable/c/b44bebdd32c9ff66ee2aebfc317ced44bedd9335"},{"url":"https://git.kernel.org/stable/c/3cfa3d8e0dc167850edeb5bf5a07757db83fd54e"},{"url":"https://git.kernel.org/stable/c/1e2c956745777e6ffdee7f30da5935741c03ee1e"},{"url":"https://git.kernel.org/stable/c/ab3e10b44ba5411779aac7afd2477917dd77750f"}],"tags":["cve.org"],"epss":0.00716,"epssPercentile":0.5284,"ingestedAt":"2026-10-16T19:46:24.385Z","slug":"CVE-2026-74282","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 3388145d258cf2c4c98278e3987296007d30672e`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 67e55b054bf8025658dc0e255057f2a6236416bd`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 96f91b8ae1a489b3eca137e7acf42cf985fb8939`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 47ed873e4ceda34098bd46d8e96b4bb13cad3a04`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < b44bebdd32c9ff66ee2aebfc317ced44bedd9335`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 3cfa3d8e0dc167850edeb5bf5a07757db83fd54e`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < 1e2c956745777e6ffdee7f30da5935741c03ee1e`\n- `Linux >= 10724cc7bb7832b482df049c20fd824d928c5eaa < ab3e10b44ba5411779aac7afd2477917dd77750f`\n- `Linux 4.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}