Vulnerability details

CVE-2026-68293

Linux Linux

net/mlx5: Fix MCIA register buffer overflow on 32 dword reads

CVSS 3.1
7.1High

Official description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix MCIA register buffer overflow on 32 dword reads The MCIA register can return up to 32 dwords (128 bytes) when the device advertises the mcia_32dwords capability, but struct mlx5_ifc_mcia_reg_bits only defines dword_0..11, leaving room for just 12 dwords (48 bytes) of data. mlx5_query_mcia() clamps the read size to mlx5_mcia_max_bytes() and then memcpy()s that many bytes out of the register, potentially reading past the end of the 'out' buffer. On kernels built with FORTIFY_SOURCE this is caught as a buffer overflow while reading the module EEPROM via ethtool: detected buffer overflow in memcpy kernel BUG at lib/string_helpers.c:1048! RIP: 0010:fortify_panic+0x13/0x20 Call Trace: mlx5_query_mcia.isra.0+0x200/0x210 [mlx5_core] mlx5_query_module_eeprom_by_page+0x4a/0xa0 [mlx5_core] mlx5e_get_module_eeprom_by_page+0xbb/0x120 [mlx5_core] eeprom_prepare_data+0xf3/0x170 ethnl_default_doit+0xf1/0x3b0 Extend the mcia_reg layout to 32 dwords.

CVSS scores

ScoreVersionSourceVector
7.1High 3.1 CVEProject cvelistV5 (CNA) (Linux) CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

VendorProductVersionsSource
Linux Linux 5.18 CVEProject cvelistV5 (CNA)
Linux Linux 271907ee2f29cd1078fd219f0778fd824fb1971c ≤ v < c8a4acc19dcdc83e1303c29d9535e5c99415a2e3 CVEProject cvelistV5 (CNA)
Linux Linux 271907ee2f29cd1078fd219f0778fd824fb1971c ≤ v < 5be4eebd5a3a198dab0adcd550e1cadca79bdfed CVEProject cvelistV5 (CNA)
Linux Linux 271907ee2f29cd1078fd219f0778fd824fb1971c ≤ v < 5ed6d41029832b11bc204d7cc326cf309d073666 CVEProject cvelistV5 (CNA)
Linux Linux 271907ee2f29cd1078fd219f0778fd824fb1971c ≤ v < 88b2a16ddac3357e3f1d528e758b51e2c945d546 CVEProject cvelistV5 (CNA)
Linux Linux 271907ee2f29cd1078fd219f0778fd824fb1971c ≤ v < 11c057d23465c7a5817a7284c896d19d54c0b616 CVEProject cvelistV5 (CNA)
Linux Linux 271907ee2f29cd1078fd219f0778fd824fb1971c ≤ v < 87b39a8c875ca744b7de69af0a8ef8874cffccf1 CVEProject cvelistV5 (CNA)

References and advisories

6
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Details

Published
2026-08-10
Last updated
2026-10-30
State
Published
Assigner (CNA)
Linux

Exploit prediction (EPSS)

0.13%
Probability of exploitation in 30 days
3.3%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
None
Technical impact
Partial

Weaknesses (CWE)

  • CWE-122
    Heap-based Buffer Overflow