CVE-2026-53194
Description
A flaw was found in the Linux kernel's kl5kusb105 USB serial driver. This buffer overflow vulnerability allows a local attacker to write data beyond the intended memory boundary (if attacker controls USB device or driver, because triggered from the internals of the device). By sending a specially crafted input to the USB serial port, an attacker can trigger an out-of-bounds write, which may lead to memory corruption. The primary consequence of this flaw is a denial of service (DoS), potentially causing system instability or crashes.
Statement
A slab out of bounds write in the USB serial kl5kusb105 transmit path occurs because klsi_105_prepare_write_buffer copies up to the full bulk out buffer size into dest plus KLSI_HDR_LEN, leaving no room for the two byte header. A local user or process that can write bulk_out_size or more bytes to the matching tty device can overflow the 64 byte bulk out buffer by KLSI_HDR_LEN bytes and corrupt adjacent slab memory.
Mitigation
To mitigate this issue, prevent module kl5kusb105 from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H
cve.org: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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