CVE-2026-68293
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
In the Linux kernel, the mlx5 driver has a buffer overflow when reading the MCIA register if the device supports 32 dword reads, but the data structure only defines 12 dwords. This can lead to out-of-bounds read and kernel panic, especially with FORTIFY_SOURCE enabled.
Risk Assessment
A local attacker could trigger a kernel panic, causing denial of service (DoS). Additionally, there is a potential for leaking kernel memory.
Recommendation
Apply the Linux kernel update containing the fix that extends the mcia_reg structure to 32 dwords. Reboot the system after the update.
Original NVD description (English source)
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.