CVE-2026-68293

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

HIGH
7.1
CVSS Score
Published: August 10, 2026 at 12:02 PM UTC
Updated: October 21, 2026 at 01:19 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.1
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

271907ee2f29cd1078fd219f0778fd824fb1971c5.18
Vendor states this is fixed in 11c057d23465c7a5817a7284c896d19d54c0b616 (fixed)
Vendor states this is fixed in 5be4eebd5a3a198dab0adcd550e1cadca79bdfed (fixed)
Vendor states this is fixed in 87b39a8c875ca744b7de69af0a8ef8874cffccf1 (fixed)
Vendor states this is fixed in 88b2a16ddac3357e3f1d528e758b51e2c945d546 (fixed)
Vendor states this is fixed in 5.18 (unaffected)
Vendor states this is fixed in 6.12.101 (unaffected)
Vendor states this is fixed in 6.18.42 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)
Vendor states this is fixed in 7.1.6 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHLinux
Vector?

Quick Info

StatusRECEIVED
CWE
CWE-122

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