GHSA-5XV7-X5QX-3WV4
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
tipc: prevent snt_unacked underflow on CONN_ACK
tipc_sk_conn_proto_rcv() subtracts the peer-supplied connection ack count from the unsigned 16-bit send counter snt_unacked without checking that it does not exceed the number of messages actually outstanding:
tsk->snt_unacked -= msg_conn_ack(hdr);
msg_conn_ack() is read straight from a received CONN_MANAGER/CONN_ACK message. If the ack count is larger than snt_unacked, the subtraction wraps to a near-maximum value, leaving tsk_conn_cong() permanently true and starving the connection of further transmits.
Validate the ACK count at the start of the CONN_ACK block and drop the message if it acknowledges more messages than are outstanding. A peer (or, for a local connection, the connected peer socket) can otherwise wedge a TIPC connection's send side by sending an oversized connection ack.
{
"affected": [],
"aliases": [
"CVE-2026-74282"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:27Z",
"severity": "HIGH"
},
"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-\u003esnt_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\u0027s send side by sending an oversized connection ack.",
"id": "GHSA-5xv7-x5qx-3wv4",
"modified": "2026-08-17T06:33:35Z",
"published": "2026-08-15T06:32:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74282"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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