Improper input validation in Eclipse Mosquitto
Priority LOW 35CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
In Eclipse Mosquitto versions 2.0.7 and earlier, the server will crash if the client tries to send a PUBLISH packet with topic length = 0.
Why it matters now
EPSS 0.01247 69th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Eclipse Foundation | Eclipse Mosquitto | up to 2.0.7 | — | No fix listed | CNA |
- Eclipse Mosquitto VendorEclipse Foundation Affected up to 2.0.7 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:eclipse:mosquitto:*:*:*:*:*:*:*:* | up to 2.0.7 | Vulnerable | Eclipse Foundation |
- cpe:2.3:a:eclipse:mosquitto:*:*:*:*:*:*:*:* Versions up to 2.0.7 Vulnerable ·Eclipse Foundation
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-34432
- 2026-10-03 Alias added: GHSA-9972-xmxv-v66x
References
More Eclipse Foundation Mosquitto vulnerabilities
- TI-2024-09749 Eclipse Mosquito: Heap Buffer Overflow in my_subscribe_callback CVSS 4.0HIGH 7.2
- TI-2018-09002 Reachable assertion in Eclipse Mosquitto CVSS 3.0HIGH 7.5
- TI-2023-12912 The broker in Eclipse Mosquitto 1.3.2 through 2.x before 2.0.16 has a memory leak that… CVSS 3.1HIGH 7.5
- TI-2017-05287 Uncontrolled resource consumption in Eclipse Mosquitto CVSS 3.0HIGH 7.5
- TI-2023-05183 Unconditionally adding an event to the epoll causes excessive CPU consumption CVSS 3.1HIGH 7.5
- TI-2018-09010 Improper authentication in Eclipse Mosquitto CVSS 3.0HIGH 8.1
Sources
- CVE-2021-34432 · CVE Program
- CVE-2021-34432 · NVD
- FIRST EPSS
- GHSA-9972-xmxv-v66x · GitHub Advisory Database · CC BY 4.0
- CVE-2021-34432 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences