---
title: "CVE-2026-107836: RIOT - Denial of Service"
description: "RIOT <= 2026.07 contains a denial of service caused by improper validation of Block2 response block size in nanocoap_sock_get_slice(), letting malicious CoAP servers crash the client and expose adjacent memory, exploit requires a malicious CoAP server."
url: https://panop.io/threat-heartbeat/CVE-2026-107836/
---

# CVE-2026-107836 RIOT - Denial of Service

RIOT <= 2026.07 contains a denial of service caused by improper validation of Block2 response block size in nanocoap\_sock\_get\_slice(), letting malicious CoAP servers crash the client and expose adjacent memory, exploit requires a malicious CoAP server.

CVSS base score 7.1 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.29% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-107836)

## Details

Type

Denial of Service

Impact

Denial Of Service, Information Disclosure

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Published

9 October 2026

Updated

15 October 2026

Weakness

[CWE-125](https://cwe.mitre.org/data/definitions/125.html)

## Vendor fix

Update to the latest version once a fix is released.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-107836](https://nvd.nist.gov/vuln/detail/CVE-2026-107836)
- [https://github.com/RIOT-OS/RIOT/commit/49b894cbe091510093273b98d92c4a17167d6839](https://github.com/RIOT-OS/RIOT/commit/49b894cbe091510093273b98d92c4a17167d6839)
- [https://github.com/RIOT-OS/RIOT/pull/22518](https://github.com/RIOT-OS/RIOT/pull/22518)
- [https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-x924-p5fq-26pc](https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-x924-p5fq-26pc)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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