Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

CVE-2026-108952RT-Thread through 5.3.0 Memory Corruption via USB CDC VCOM Driver

Medium 4.6

In plain English

A medium-severity type confusion in rt-thread from RT-Thread. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).

Severity (CVSS 3.1)4.6Medium

Exploit odds (30 days)0.2%top 90.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 Serial V2 rt_serial_rx_fifo in _function_enable(). A connected USB host configuring the CDC device triggers writes past the ring buffer into struct vcom members and an invalid rt_free() on close, causing denial of service.

Affected products (as reported)

Vendor	Product	Versions
RT-Thread	rt-thread	0 – through 5.3.0

Weakness: CWE-843 · Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/RT-Thread/rt-thread/issues/11739 issue-tracking
https://github.com/RT-Thread/rt-thread/pull/11770 issue-tracking, patch
https://github.com/RT-Thread/rt-thread/commit/ceef6e0ccd646aef61b907aeb9f29269d1caba50 patch
https://github.com/RT-Thread/rt-thread/blob/99428a1e7f7447955aa860f7c969273a12095b8f/components/legacy/usb/usbdevice/class/cdc_vcom.c#L518 technical-description
https://github.com/RT-Thread/rt-thread product
VulnCheck Advisory: RT-Thread through 5.3.0 Memory Corruption via USB CDC VCOM Driver third-party-advisory