{"id":"CVE-2026-63830","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skmsg: preserve sg.copy across SG transforms\n\nThe sk_msg sg.copy bitmap is part of the scatterlist entry ownership\nstate","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skmsg: preserve sg.copy across SG transforms\n\nThe sk_msg sg.copy bitmap is part of the scatterlist entry ownership\nstate. A set bit tells sk_msg_compute_data_point…","severity":"critical","cvss":9.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L","published":"2026-07-19","updated":"2026-08-17","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63830","references":[{"url":"https://git.kernel.org/stable/c/0eb4c16c4adb262763bda870a8ed38a1a9dec7ec","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1acdd14c0990dd1cd4b6534f00366d2e6dfce05f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/21ed9540a8e1906dfcbc1bb82ba9b4de4fa4bd6d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/31a110642b5fb5e61940cbcfb503445ac4f28017","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/406e8a651a7b854c41fecd5117bb282b3a6c2c6b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9bb86d8184b37503816150c4a6ad3c17dfdbe827","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d22cc92bc41290e5783a72375e0843d9435f6001","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f126eed589eec6f201405abbc398844042ef6d57","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00372,"epssPercentile":0.28335,"ingestedAt":"2026-08-17T05:47:50.400Z","slug":"CVE-2026-63830","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: skmsg: preserve sg.copy across SG transforms\n\nThe sk_msg sg.copy bitmap is part of the scatterlist entry ownership\nstate. A set bit tells sk_msg_compute_data_pointers() not to expose the\nentry through writable BPF ctx->data. This protects entries backed by\npages that are not private to the sk_msg, such as splice-backed file\npage-cache pages.\n\nSeveral sk_msg transform paths move, copy, split, or compact\nmsg->sg.data[] entries without moving the matching sg.copy bit. This can\nmake an externally backed entry arrive at a new slot with a clear copy\nbit. A later SK_MSG verdict can then expose sg_virt(sge) as writable\nctx->data and BPF stores can modify the original page cache.\n\nKeep sg.copy synchronized with sg.data[] whenever entries are\ntransferred, shifted, split, or copied into a new sk_msg. Clear the bit\nwhen an entry is replaced by a newly allocated private page or freed.\nThis covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(),\nsk_msg_xfer(), and tls_split_open_record(), including the partial tail\nentry created during TLS open-record splitting.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":52,"depthScoreParts":{"impact":51.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}