RT-Thread through 5.3.0 contains a memory corruption vulnerability in the legacy USB CDC virtual COM port driver that aliases rx_ringbuffer as a… (CVE-2026-108952)
Description
RT-Thread versions through 5.3.0 have a memory corruption vulnerability in the legacy USB CDC virtual COM port driver. This flaw occurs because the rx_ringbuffer is aliased as a Serial V2 rt_serial_rx_fifo in the _function_enable() function. When a connected USB host configures the CDC device, it can cause writes beyond the ring buffer into adjacent memory structures and trigger an invalid rt_free() call upon device close. This results in a denial of service condition.
CVSS v3.1
Score 4.6medium
Affected software
pkg:github/rt-thread/rt-threadRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-108952 describes a memory corruption vulnerability in RT-Thread through version 5.3.0 within the legacy USB CDC virtual COM port driver. The vulnerability arises from aliasing the rx_ringbuffer as a Serial V2 rt_serial_rx_fifo in the _function_enable() function. A connected USB host configuring the CDC device can cause writes that exceed the bounds of the ring buffer, overwriting members of the struct vcom and leading to an invalid rt_free() call when the device is closed. This memory corruption causes a denial of service.
Potential Impact
The vulnerability leads to denial of service by corrupting memory and causing invalid free operations when the USB CDC device is closed. There is no indication of confidentiality or integrity impact. The CVSS score is 4.6 (medium severity), reflecting that the attack requires physical or local access (adjacent network vector) and results in availability disruption only.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, avoid using the legacy USB CDC virtual COM port driver with untrusted USB hosts or disable the affected functionality if possible.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-x4hq-c3c6-m368
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-108952"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6acd556e2cdf04f656da88ca
Added to database: 10/12/2026, 21:47:26 UTC
Last enriched: 10/12/2026, 22:07:59 UTC
Last updated: 10/12/2026, 22:07:59 UTC
Views: 7
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