What’s Vulnerable › Vulnerabilities

CVE-2026-22214: RIOT OS <= 2026.01-devel-317 Stack-Based Buffer Overflow in ethos Serial Frame Parser

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-12 · updated 2026-07-14
• Weakness: CWE-121

Description

RIOT OS versions up to and including 2026.01-devel-317 contain a stack-based buffer overflow vulnerability in the ethos utility due to missing bounds checking when processing incoming serial frame data. The vulnerability occurs in the _handle_char() function, where incoming frame bytes are appended to a fixed-size stack buffer without verifying that the current write index remains within bounds. An attacker capable of sending crafted serial or TCP-framed input can cause the current write index to exceed the buffer size, resulting in a write past the end of the stack buffer. This condition leads to memory corruption and application crash.

Affected products

• RIOT-OS RIOT: before 2025.10; 2026.01-devel, 2026.01-rc1 — fixed in 2025.10

How to fix

Upgrade to a fixed version: RIOT-OS RIOT 2025.10. Check the vendor advisory for mitigations.

References

• https://github.com/RIOT-OS/RIOT
• https://seclists.org/fulldisclosure/2026/Jan/16
• https://www.riot-os.org/
• https://www.vulncheck.com/advisories/riot-os-stack-based-buffer-overflow-in-ethos-serial-frame-parser

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