NanoMQ MQTT Broker up to 0.24.6 Byte Integer Parser get_var_integer out-of-bounds

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.4$0-$5k0.00

Summaryinfo

A vulnerability has been found in NanoMQ MQTT Broker up to 0.24.6 and classified as problematic. The impacted element is the function get_var_integer of the component Byte Integer Parser. The manipulation leads to out-of-bounds. This vulnerability is listed as CVE-2026-21888. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in NanoMQ MQTT Broker up to 0.24.6. It has been rated as problematic. This issue affects the function get_var_integer of the component Byte Integer Parser. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is availability. The summary by CVE is:

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer() accepts 5-byte varints without bounds checks; reliably triggers OOB read / crash when built with ASan. This affects 0.24.6 and earlier.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-21888 since 01/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/05/2026 CVE reserved
03/11/2026 +65 days Advisory disclosed
03/11/2026 +0 days VulDB entry created
03/14/2026 +3 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-21888 (🔒)
GCVE (CVE): GCVE-0-2026-21888
GCVE (VulDB): GCVE-100-350423

Entryinfo

Created: 03/11/2026 16:54
Updated: 03/14/2026 12:43
Changes: 03/11/2026 16:54 (63), 03/14/2026 12:43 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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