{"id":"CVE-2026-68293","title":"net/mlx5: Fix MCIA register buffer overflow on 32 dword reads","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5: Fix MCIA register buffer overflow on 32 dword reads\n\nThe MCIA register can return up to 32 dwords (128 bytes) when the device\nadvertises the mcia_32dwords cap…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 5be4eebd5a3a198dab0adcd550e1cadca79bdfed","Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 87b39a8c875ca744b7de69af0a8ef8874cffccf1","Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 88b2a16ddac3357e3f1d528e758b51e2c945d546","Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 11c057d23465c7a5817a7284c896d19d54c0b616","Linux 5.18"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T15:46:41.032744Z"},"published":"2026-08-10","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:53:06.615Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-68293","references":[{"url":"https://git.kernel.org/stable/c/5be4eebd5a3a198dab0adcd550e1cadca79bdfed"},{"url":"https://git.kernel.org/stable/c/87b39a8c875ca744b7de69af0a8ef8874cffccf1"},{"url":"https://git.kernel.org/stable/c/88b2a16ddac3357e3f1d528e758b51e2c945d546"},{"url":"https://git.kernel.org/stable/c/11c057d23465c7a5817a7284c896d19d54c0b616"}],"tags":["cve.org"],"epss":0.00138,"epssPercentile":0.02859,"ingestedAt":"2026-10-16T17:24:46.859Z","slug":"CVE-2026-68293","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5: Fix MCIA register buffer overflow on 32 dword reads\n\nThe MCIA register can return up to 32 dwords (128 bytes) when the device\nadvertises the mcia_32dwords capability, but struct\nmlx5_ifc_mcia_reg_bits only defines dword_0..11, leaving room for just\n12 dwords (48 bytes) of data.\n\nmlx5_query_mcia() clamps the read size to mlx5_mcia_max_bytes() and then\nmemcpy()s that many bytes out of the register, potentially reading past\nthe end of the 'out' buffer. On kernels built with FORTIFY_SOURCE this\nis caught as a buffer overflow while reading the module EEPROM via\nethtool:\n\n  detected buffer overflow in memcpy\n  kernel BUG at lib/string_helpers.c:1048!\n  RIP: 0010:fortify_panic+0x13/0x20\n  Call Trace:\n   mlx5_query_mcia.isra.0+0x200/0x210 [mlx5_core]\n   mlx5_query_module_eeprom_by_page+0x4a/0xa0 [mlx5_core]\n   mlx5e_get_module_eeprom_by_page+0xbb/0x120 [mlx5_core]\n   eeprom_prepare_data+0xf3/0x170\n   ethnl_default_doit+0xf1/0x3b0\n\nExtend the mcia_reg layout to 32 dwords.\n\n## Affected\n\n- `Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 5be4eebd5a3a198dab0adcd550e1cadca79bdfed`\n- `Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 87b39a8c875ca744b7de69af0a8ef8874cffccf1`\n- `Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 88b2a16ddac3357e3f1d528e758b51e2c945d546`\n- `Linux >= 271907ee2f29cd1078fd219f0778fd824fb1971c < 11c057d23465c7a5817a7284c896d19d54c0b616`\n- `Linux 5.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}