Out-of-bounds read via RX length underflow
Published Jul 25, 2026 · Updated Jul 25, 2026
Out-of-bounds read in the kalmia USB network driver in Linux Kernel allows physically proximate attackers to read past an RX buffer. kalmia_rx_fixup() subtracts two six-byte headers from a short frame as an unsigned 16-bit value, underflows the length, and uses a device-supplied length beyond the buffer. Exploitation requires a connected USB device able to send a 6-to-11-byte frame or short trailing remainder; no consequence beyond the kernel read is established.
Summary
What happened
Out-of-bounds read in the kalmia USB network driver in Linux Kernel allows physically proximate attackers to read past an RX buffer. kalmia_rx_fixup() subtracts two six-byte headers from a short frame as an unsigned 16-bit value, underflows the length, and uses a device-supplied length beyond the buffer. Exploitation requires a connected USB device able to send a 6-to-11-byte frame or short trailing remainder; no consequence beyond the kernel read is established.
The record
- CVE
- CVE-2026-64351
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1200
- Attack vector
- physical
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.0
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <391706889a5112feafdc0c68db3ecc7ed325d09c
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <46ab32870d010e9a057bc5659cea22b7e728ca88
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <47b6bcef6e679593d2e86e04ee72c46a4e2f7139
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <51e65f1d78457ea4f9513d90ab22c9dccbb35110
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <c466097d85d52f3aa200736cb4759e66d4bbf6e3
- Affected versionversion=d40261236e8e278cb1936cb5e934262971692b10 <e24eb271061db384a3c3ef6f107fe515e68ef222
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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