CVE Tools
Sign in

CVE-2026-21888

MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer()

Published: Mar 11, 2026Updated: Mar 17, 2026 Sources: CVE List NVDCWE-125
NVD MITRE
7.5CVSSHIGH
EPSS Score
0.3%
Top 78.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-125

Affected Products

nanomqnanomq
On-prem
Networking Infrastructure / network-management
nanomqemqx
Mixed
Cloud & SaaS / api-gateway
nanomqoss-projectCNNetworking Infrastructureaka nanomq, nanonng
emqxcommercialCNCloud & SaaS

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/nanomq/nanomq/security/advisories/GHSA-cggc-6m7w-j7x5
github.com
https://github.com/nanomq/nanomq/issues/2192
github.com

Timeline

Published
Mar 11, 2026
Last Updated
Mar 17, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-21888 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows