{"id":"CVE-2026-68278","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix buffer overflows in sideband chunk accumulation\n\ndrm_dp_sideband_append_payload() has three related bugs when processing\ndevice-provided sideband reply …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix buffer overflows in sideband chunk accumulation\n\ndrm_dp_sideband_append_payload() has three related bugs when processing\ndevice-provided sideband reply …","severity":"none","published":"2026-08-10","updated":"2026-08-23","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-68278","references":[{"url":"https://git.kernel.org/stable/c/1e5827839ad0ceb0079d1560c321fa3656b54f21","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4d5109075a787de28c9e89940f9dee45269f91fa","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/53937a2787d29c7a460e984dc4f20ff6ac91dc65","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/55bd5e685bda455b9b50c835f8c8442d52a344a3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a6366b551079c79bf7bdbadd74c97358bcfe2d58","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d4e05dedb252ed3e540a0c9be511e427f098110a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ef0dbcc200c3389f1f781ab181932a97e54b51af","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ef2ecb6cf268debf3890df99fea01b6452dcf78e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00238,"epssPercentile":0.15067,"ingestedAt":"2026-08-23T13:48:06.902Z","slug":"CVE-2026-68278","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix buffer overflows in sideband chunk accumulation\n\ndrm_dp_sideband_append_payload() has three related bugs when processing\ndevice-provided sideband reply data:\n\n1. Zero-length curchunk_len underflow: msg_len is a 6-bit field taken\n   directly from the DP sideband header. If a device sends msg_len=0,\n   curchunk_len is set to zero. The condition (curchunk_idx >= curchunk_len)\n   is immediately true, and curchunk_len-1 wraps to 255 (u8 underflow).\n   drm_dp_msg_data_crc4() reads 255 bytes from chunk[48], then memcpy()\n   writes 255 bytes into msg[], both far out of bounds.\n\n2. chunk[48] overflow: curchunk_len can reach 63 (6-bit field). chunk[] is\n   only 48 bytes. Multi-iteration payload assembly appends 16-byte blocks\n   until curchunk_idx reaches curchunk_len, writing up to 15 bytes past\n   the end of chunk[] into msg[].\n\n3. msg[256] overflow: each chunk contributes (curchunk_len-1) bytes to\n   msg[]. No check ensures curlen + (curchunk_len-1) stays within msg[256],\n   so the memcpy can spill into adjacent struct fields.\n\nAll three are reachable from any DP MST device that can forge sideband\nreply messages on a physical connection.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}