CVE-2026-26399

Memory corruption via dangling PWM timer handle

Published Apr 20, 2026 · Updated Apr 20, 2026

Stack-use-after-return in Arduino_Core_STM32 before 1.7.0 allows local users to corrupt memory through PWM timer initialization. The pwm_start() function creates a TIM_HandleTypeDef on its stack and lets HAL initialization retain its address in the global timer registry, leaving interrupt handlers to dereference an invalid object after return. Reachability requires firmware built with the affected core and a path that lets attacker-controlled input influence stack reuse and interrupt timing; the bounded result is memory corruption, including a crash or HardFault.

CVSS severity5.3
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-use-after-return in Arduino_Core_STM32 before 1.7.0 allows local users to corrupt memory through PWM timer initialization. The pwm_start() function creates a TIM_HandleTypeDef on its stack and lets HAL initialization retain its address in the global timer registry, leaving interrupt handlers to dereference an invalid object after return. Reachability requires firmware built with the affected core and a path that lets attacker-controlled input influence stack reuse and interrupt timing; the bounded result is memory corruption, including a crash or HardFault.

The record

CVE
CVE-2026-26399
Published
Apr 20, 2026
Updated
Apr 20, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-562
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-562Return of Stack Variable Address

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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