Vulnerability · Published Apr 20, 2026 · Assigned by mitre
CVE-2026-26399
Medium 5.3
In plain English
A medium-severity security flaw in the arduino package (Ubuntu). 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 8% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official description
A stack-use-after-return issue exists in the Arduino_Core_STM32 library prior to version 1.7.0. The pwm_start() function allocates a TIM_HandleTypeDef structure on the stack and passes its address to HAL initialization routines, where it is stored in a global timer handle registry. After the function returns, interrupt service routines may dereference this dangling pointer, resulting in memory corruption.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | arduino | no fix listed | UBUNTU-CVE-2026-26399 |
| Ubuntu:24.04:LTS | arduino | no fix listed | UBUNTU-CVE-2026-26399 |
| Ubuntu:25.10 | arduino | no fix listed | UBUNTU-CVE-2026-26399 |
| Ubuntu:26.04:LTS | arduino | no fix listed | UBUNTU-CVE-2026-26399 |
| Ubuntu:26.10 | arduino | no fix listed | UBUNTU-CVE-2026-26399 |
Affected products (as reported)
Weakness: CWE-562 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L