What is CVE-2026-26399?

CVE-2026-26399 is a medium-severity vulnerability in N/a, classified under CWE-562. CVSS score: 5.3/10. Published 2026-04-20.

How severe is CVE-2026-26399?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Is CVE-2026-26399 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in N/a

CVE-2026-26399

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 i…

EPSS: 0.002 (7.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.

Affected products

N/a — versions n/a

Weakness classification (CWE)

CWE-562

Public proof-of-concept exploits

Acen28/CVE-2026-26399-Disclosure

References

Frequently asked questions

What is CVE-2026-26399?: CVE-2026-26399 is a medium-severity vulnerability in N/a, classified under CWE-562. CVSS score: 5.3/10. Published 2026-04-20.
How severe is CVE-2026-26399?: Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2026-26399 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.